The Marines in Halo: Infinite? Marines or Army?

Games Halo Infinite
1

So I came to the realization that the UNSC Marines that we presumably see in the first Halo: Infinite trailer might not be Marines at all. There has been no actual confirmation that they were Marines. In fact, strictly based off of what we’ve seen of their armor in the past they could very well be UNSC Army. The CH252 helmet that Marines wear throughout the series all fall under the same model. So why are there so many different variations when there are no lore-based confirmations that there are actually different renditions of the helmet? (On a similar note, the thing that most bothered me about the Reach helmets were that they didn’t feel like the classic Marine helmets. That being angular, olive drab/dirt brown, and simply iconic lol). The troops we see in Reach are almost entirely UNSC Army and their standard issue weapons were the MA37 AR and the M392 DMR, as well as that specific type of armor design. The Halo: Infinite Marines could possibly be UNSC Army. I enjoy the Halo universe bringing up different branches but I still prefer the Marines since they’ve been an integral part of Halo from the start. Any person who has a background of military or an understanding can understand that every branch likes to be distinct. The thing that bothers me most though is there is very little distinction between the branches of the UNSC when in real life there are truly some distinctions based off of modern militaries. I think it would add some depth to introduce the other branches more but keep the Marines in their respective roles in the Halo universe. So my main point here is that I would like to know if there has been any confirmations on the return of the UNSC Marines (and other branches) as well as if there have been any other variations of other Marine armor renditions (i.e Halo 3, Halo 4/5, Halo Wars) shown in leaks/images/toys/etc.?

TL;DR: The Halo: Infinite Marines in the trailer might not be Marines, but could be UNSC Army. I’m looking for any confirmation if that is the case.

This is my first topic here on the Halo forums so thank you guys for being awesome! Keep it civil and express your opinions/facts properly.

2

Yeah, I brought that up too in the Grunt discussion. Apparently the nerf gun from few weeks back is even based on the MA40, so if true this is indeed a new model of the army AR. We’re most probably not working with the marines this time around and I’m fine with that! I’m curious to see Chief’s interaction with them!

3

So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.

Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.

4

> 2535424784569825;3:
> So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
>
> Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.

The Army did more than planetary defense. They simply didn’t deploy with the Navy as naval attachments to ships the way Marines do (and did historically).

there’s this pervasive myth that the Marine Corps is America’s offensive force while the Army is defensive. This is nonsense. The Marine Corps is maritime while the Army is continental. That’s the true distinguisher.

5

> 2535458940440268;4:
> > 2535424784569825;3:
> > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> >
> > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
>
> The Army did more than planetary defense. They simply didn’t deploy with the Navy as naval attachments to ships the way Marines do (and did historically).
>
> there’s this pervasive myth that the Marine Corps is America’s offensive force while the Army is defensive. This is nonsense. The Marine Corps is maritime while the Army is continental. That’s the true distinguisher.

While what you say may be true, I have not encountered any mention of offensive Army operations within the Halo lore. Granted, I haven’t read many of the books.

Could you provide me with some examples?

6

The bdu that the army soldiers wore in Halo Reach was shared by the marines and airmen in the same game, like some all-cross-branch variant. Considering you’re on expiditionary work in Halo Infinite (like many past halo titles), those are likely marines as well since they’re suppose to be the first into unknown areas to fight. The army is less flexible and more garrison-ish than expeditionary, sort of like the real life US army that inspires it. As for the different variants, my presumption for the differences is based on whereever their stationed or the era of the when game takes place in.

7

> 2535417286073297;1:
> So I came to the realization that the UNSC Marines that we presumably see in the first Halo: Infinite trailer might not be Marines at all. There has been no actual confirmation that they were Marines. In fact, strictly based off of what we’ve seen of their armor in the past they could very well be UNSC Army. The CH252 helmet that Marines wear throughout the series all fall under the same model. So why are there so many different variations when there are no lore-based confirmations that there are actually different renditions of the helmet? (On a similar note, the thing that most bothered me about the Reach helmets were that they didn’t feel like the classic Marine helmets. That being angular, olive drab/dirt brown, and simply iconic lol). The troops we see in Reach are almost entirely UNSC Army and their standard issue weapons were the MA37 AR and the M392 DMR, as well as that specific type of armor design. The Halo: Infinite Marines could possibly be UNSC Army. I enjoy the Halo universe bringing up different branches but I still prefer the Marines since they’ve been an integral part of Halo from the start. Any person who has a background of military or an understanding can understand that every branch likes to be distinct. The thing that bothers me most though is there is very little distinction between the branches of the UNSC when in real life there are truly some distinctions based off of modern militaries. I think it would add some depth to introduce the other branches more but keep the Marines in their respective roles in the Halo universe. So my main point here is that I would like to know if there has been any confirmations on the return of the UNSC Marines (and other branches) as well as if there have been any other variations of other Marine armor renditions (i.e Halo 3, Halo 4/5, Halo Wars) shown in leaks/images/toys/etc.?
>
> TL;DR: The Halo: Infinite Marines in the trailer might not be Marines, but could be UNSC Army. I’m looking for any confirmation if that is the case.
>
> This is my first topic here on the Halo forums so thank you guys for being awesome! Keep it civil and express your opinions/facts properly.

wow i never actually thought about that

8

> 2533274870308953;6:
> The bdu that the army soldiers wore in Halo Reach was shared by the marines and airmen in the same game, like some all-cross-branch variant. Considering you’re on expiditionary work in Halo Infinite (like many past halo titles), those are likely marines as well since they’re suppose to be the first into unknown areas to fight. The army is less flexible and more garrison-ish than expeditionary, sort of like the real life US army that inspires it. As for the different variants, my presumption for the differences is based on whereever their stationed or the era of the when game takes place in.

I see this misconception a lot. While I won’t get into the fictional Army of the Halo games, it’s not accurate to say the Army is garrison/defensive while Marines are offensive. Both branches function both ways and the unit has much more to do with it than the branch. For example, much of the Marines’ strategy in the Pacific calls for defensive garrisoning along island chains, while the Army is focused on bringing large mechanized units to the fight for massive offensive battles against the Chinese PLA vanguard force.

A better, more accurate way to describe both branches would be to call the Marine Corps maritime and the Army continental. That’s the biggest difference. The notion that the Marines are an offensive force while the Army is a garrison force is a common misconception that pisses off a good number of US Army soldiers I know from some pretty high-speed units who have done more than any one person’s fair share of offensive fighting in places like Iraq and Afghanistan. People seem to forget it was the Army that defeated Saddam in 1991 and again led the charge to Baghdad in 2003. It was the Army that conducted the first major battle of the war in Afghanistan, Operation Anaconda.

god, none of this has anything to do with Halo and I feel a little silly posting it—I just can’t stand how many people post Marine Corps PR as if it’s fact. :slight_smile:

9

> 2535424784569825;5:
> > 2535458940440268;4:
> > > 2535424784569825;3:
> > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > >
> > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> >
> > The Army did more than planetary defense. They simply didn’t deploy with the Navy as naval attachments to ships the way Marines do (and did historically).
> >
> > there’s this pervasive myth that the Marine Corps is America’s offensive force while the Army is defensive. This is nonsense. The Marine Corps is maritime while the Army is continental. That’s the true distinguisher.
>
> While what you say may be true, I have not encountered any mention of offensive Army operations within the Halo lore. Granted, I haven’t read many of the books.
>
> Could you provide me with some examples?

The Army isn’t discussed much in Halo because the games (and therefore the books) roll deep with the “Space Marine” trope. The Army battles we know of were mostly in our own solar system, but they were also deployed at a number of large engagements across the galaxy. You have to remember that the events in the Halo trilogy follow Chief across a period of weeks, not years. As such, we only see a few major battles from the perspective of only a few large ships and their Marine detachments.

in Halo 4, though, we see the Infinity, which is crewed by a joint force of UNSC Army, Air Force, Marines, and Navy. Halo Reach is also full of Army Troopers, and while Reach is indeed a defensive fight, those Spartans are Army too and fought all over in the weeks leading to Reach. It’s also fair to say that most of the war with the Covenant was defensive. Aside from some fleet battles and some special operations, most of the engagements were on human planets until the Chief found Halo, Delta Halo, and the Ark. and again, we only follow a handful of ships in each of those battles.

10

I think that Marines should definitely still be the “standard” Halo troop as they are an iconic part of the franchise, but I do very much enjoy some diversity in the branches being showcased, which is why the inclusion of the Army in Reach was really enjoyable to me.

11

Looks like the UNSC Army to me given the MA40 Assault Rifle, which is an Army standard issue.

12

> 2533274883624877;11:
> Looks like the UNSC Army to me given the MA40 Assault Rifle, which is an Army standard issue.

I really hope so.

13

> 2535458940440268;9:
> > 2535424784569825;5:
> > > 2535458940440268;4:
> > > > 2535424784569825;3:
> > > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > > >
> > > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> > >
> > > ~
> >
> > ~
>
> in Halo 4, though, we see the Infinity, which is crewed by a joint force of UNSC Army, Air Force, Marines, and Navy. Halo Reach is also full of Army Troopers, and while Reach is indeed a defensive fight, those Spartans are Army too and fought all over in the weeks leading to Reach. It’s also fair to say that most of the war with the Covenant was defensive. Aside from some fleet battles and some special operations, most of the engagements were on human planets until the Chief found Halo, Delta Halo, and the Ark. and again, we only follow a handful of ships in each of those battles.

Was ‘Spartans are Army too’ a typo? At that time all Spartans were Naval, NOBLE was just assigned to an Army unit, much as a modern Air Base can have Marines and other branch personnel attached.

Regardless, the primary offenses all branches of the UNSC participated in- Army and Marines alike- were counteroffensives or retaking lost territory during the Human-Covenant war.

14

I think it’s the Marines in the upcoming Halo Infinite. They will most likely appeared in Halo Infinite. I wouldn’t mind seeing UNSC Army coming back in the new Halo video game. It’s been a long time since they appeared in Halo Reach. I also would love to see ODST Troopers coming back in Halo Infinite.

15

> 2535417286073297;1:
> So I came to the realization that the UNSC Marines that we presumably see in the first Halo: Infinite trailer might not be Marines at all. There has been no actual confirmation that they were Marines. In fact, strictly based off of what we’ve seen of their armor in the past they could very well be UNSC Army. The CH252 helmet that Marines wear throughout the series all fall under the same model. So why are there so many different variations when there are no lore-based confirmations that there are actually different renditions of the helmet? (On a similar note, the thing that most bothered me about the Reach helmets were that they didn’t feel like the classic Marine helmets. That being angular, olive drab/dirt brown, and simply iconic lol). The troops we see in Reach are almost entirely UNSC Army and their standard issue weapons were the MA37 AR and the M392 DMR, as well as that specific type of armor design. The Halo: Infinite Marines could possibly be UNSC Army. I enjoy the Halo universe bringing up different branches but I still prefer the Marines since they’ve been an integral part of Halo from the start. Any person who has a background of military or an understanding can understand that every branch likes to be distinct. The thing that bothers me most though is there is very little distinction between the branches of the UNSC when in real life there are truly some distinctions based off of modern militaries. I think it would add some depth to introduce the other branches more but keep the Marines in their respective roles in the Halo universe. So my main point here is that I would like to know if there has been any confirmations on the return of the UNSC Marines (and other branches) as well as if there have been any other variations of other Marine armor renditions (i.e Halo 3, Halo 4/5, Halo Wars) shown in leaks/images/toys/etc.?
>
> TL;DR: The Halo: Infinite Marines in the trailer might not be Marines, but could be UNSC Army. I’m looking for any confirmation if that is the case.
>
> This is my first topic here on the Halo forums so thank you guys for being awesome! Keep it civil and express your opinions/facts properly.

Pretty sure in Canon almost all branches of military have been unified under the UNSC banner. While they might be the army branch I doubt we’ll get any confirmation and they’ll just be referred as marines to simplify it for casual fans that are used to calling them marines. Even the soldiers stationed on Meridian in Halo 5 which aren’t even part of the UNSC are referred to as Marines I’m pretty sure.

16

> 2535462145233570;13:
> > 2535458940440268;9:
> > > 2535424784569825;5:
> > > > 2535458940440268;4:
> > > > > 2535424784569825;3:
> > > > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > > > >
> > > > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> > > >
> > > > ~
> > >
> > > ~
> >
> > in Halo 4, though, we see the Infinity, which is crewed by a joint force of UNSC Army, Air Force, Marines, and Navy. Halo Reach is also full of Army Troopers, and while Reach is indeed a defensive fight, those Spartans are Army too and fought all over in the weeks leading to Reach. It’s also fair to say that most of the war with the Covenant was defensive. Aside from some fleet battles and some special operations, most of the engagements were on human planets until the Chief found Halo, Delta Halo, and the Ark. and again, we only follow a handful of ships in each of those battles.
>
> Was ‘Spartans are Army too’ a typo? At that time all Spartans were Naval, NOBLE was just assigned to an Army unit, much as a modern Air Base can have Marines and other branch personnel attached.
>
> Regardless, the primary offenses all branches of the UNSC participated in- Army and Marines alike- were counteroffensives or retaking lost territory during the Human-Covenant war.

I was referring primarily to Spartans Thorn and Tanaka, both of whom were Army before they became Spartans. In the Reach era days, ONI ran the program, but NOBLE was Army. They are Army branch Spartans (and this was before the Spartans were their own branch). So yes, you could think of them as “on loan” to the Army.

17

Probably a classic redesign for the Infinite marines.

18

> 2535458940440268;16:
> > 2535462145233570;13:
> > > 2535458940440268;9:
> > > > 2535424784569825;5:
> > > > > 2535458940440268;4:
> > > > > > 2535424784569825;3:
> > > > > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > > > > >
> > > > > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> > > > >
> > > > > ~
> > > >
> > > > ~
> > >
> > > ~
> >
> > ~
>
> I was referring primarily to Spartans Thorn and Tanaka, both of whom were Army before they became Spartans. In the Reach era days, ONI ran the program, but NOBLE was Army. They are Army branch Spartans (and this was before the Spartans were their own branch). So yes, you could think of them as “on loan” to the Army.

Uh… Hard no. Noble was attached to the Army; That does not mean they were Army. They all held Navy ratings, but they were not “Army Branch” Spartans any more than a Naval Corpsman is a “Marine Branch” Medic when attached to a Marine Corps unit. They were still Navy even if they were in an Army unit.

19

> 2535462145233570;18:
> > 2535458940440268;16:
> > > 2535462145233570;13:
> > > > 2535458940440268;9:
> > > > > 2535424784569825;5:
> > > > > > 2535458940440268;4:
> > > > > > > 2535424784569825;3:
> > > > > > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > > > > > >
> > > > > > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> > > > > >
> > > > > > ~
> > > > >
> > > > > ~
> > > >
> > > > ~
> > >
> > > ~
> >
> > I was referring primarily to Spartans Thorn and Tanaka, both of whom were Army before they became Spartans. In the Reach era days, ONI ran the program, but NOBLE was Army. They are Army branch Spartans (and this was before the Spartans were their own branch). So yes, you could think of them as “on loan” to the Army.
>
> Uh… Hard no. Noble was attached to the Army; That does not mean they were Army. They all held Navy ratings, but they were not “Army Branch” Spartans any more than a Naval Corpsman is a “Marine Branch” Medic when attached to a Marine Corps unit. They were still Navy even if they were in an Army unit.

I’ll try to find the forum where one of the Reach writers confirmed they transferred to the Army. If I can find the link I’ll edit this and include it. Their status is a bit more complicated than just serving with the Army.

20

> 2535458940440268;19:
> > 2535462145233570;18:
> > > 2535458940440268;16:
> > > > 2535462145233570;13:
> > > > > 2535458940440268;9:
> > > > > > 2535424784569825;5:
> > > > > > > 2535458940440268;4:
> > > > > > > > 2535424784569825;3:
> > > > > > > > So, to address your issues, I’ll go ahead and say that, at the time of Halo’s original development, the US military (which is the primary basis of the UNSC Defense Forces, being based on the USCM of Aliens as well as their use of US Medals in Halo 2 and 3) had no major distinctions between branches. Everyone wore the same combat uniform, the BDU, and wore ALICE belts and suspenders. The “distinction between branches on the battlefield” is a 21st century invention, kickstarted by the US Marines, who were tired of being called soldiers, and the other branches followed suit.
> > > > > > > >
> > > > > > > > Within the lore, the armor being used by the marines (they’d have to be marines if they’re on a Halo, as the Army is established within the lore to be responsible for planetary defense) is established to be a component of the “cross-branch BDU,” which like the name implies, is used by all branches of the UNSCDF. This was confirmed on the level, Pillar of Autumn, in Halo: Reach, as the servicemen in blue uniforms with brown armor are marines, not soldiers, and in the remaster of CE, in which all members of the Autumn’s marine detachment are wearing it as well.
> > > > > > >
> > > > > > > ~
> > > > > >
> > > > > > ~
> > > > >
> > > > > ~
> > > >
> > > > ~
> > >
> > > I was referring primarily to Spartans Thorn and Tanaka, both of whom were Army before they became Spartans. In the Reach era days, ONI ran the program, but NOBLE was Army. They are Army branch Spartans (and this was before the Spartans were their own branch). So yes, you could think of them as “on loan” to the Army.
> >
> > Uh… Hard no. Noble was attached to the Army; That does not mean they were Army. They all held Navy ratings, but they were not “Army Branch” Spartans any more than a Naval Corpsman is a “Marine Branch” Medic when attached to a Marine Corps unit. They were still Navy even if they were in an Army unit.
>
> I’ll try to find the forum where one of the Reach writers confirmed they transferred to the Army. If I can find the link I’ll edit this and include it. Their status is a bit more complicated than just serving with the Army.

Here’s my source on NOBLE team still being considered Navy personnel. That, and personal experience (As the UNSC systems are based very heavily on US Military structure).

http://forums.bungie.org/halo/archive37.pl?read=1085710 (Which is in turn sourced from Halopedia)

Basically, yes, they operate under the Army; But administratively speaking, like the aforementioned Naval Corpsman example, they are still Navy. This is why Carter, Kat, and presumably Six (Who is an O-3, not an O-1 or O-2) use Naval Ranks; Though the UNSC Army has a Warrant Officer structure, the Navy also has Warrant Officers; Which explains Jorge, Jun, and Emile, who are all Warrant Officers and certainly part of the UNSC Navy.