> Still, I can’t believe that humans would end up joining the Covenant. They would have to be mass converted or at least be willing to surrender their empire to an alien race.
I think they would if extinction seemed certain.
> What position would humans get in the Covenant caste system? Would humanity be higher up on the chain under Brutes or would the Prophets condition humans to be cannon fodder and workers like the grunts?
Hard to say. I think that where humans are placed and how humans are viewed would be different, and that these things would be different depending on what species you ask.
Humans don’t offer very many skills unique to the Covenant at the present moment. The UNSC is a primitive backwater race that has no experience in inter-species and interstellar diplomacy, no knowledge of the surrounding space or polities, it has a very small and very technologically limited navy and military with quite ineffective soldiers compared to what the Covenant field due to their physical frailty and technological shortcomings, and they have very limited access to resources, trivial military-industrial power, population size, economic strength and is also socially unprepared for encountering other alien lifeforms. Humanity joining the Covenant would be like strapping a dynamo to the side of a power station.
Hence I believe that Humans would get placed quite low, as low as Grunts I’m afraid to say. At least the Jackals present acute economic advantages to the Covenant and hence already fill that role. Even though Humanity has a well organized military and acute strategic awareness in principle, the Elites already have that covered and actually exceed humanity there. As far as scientists and Engineers are concerned, the Covenant already has Drones and Huragok for that, and this attribute wouldn’t be as highly sought after either due to the Covenant’s relative lack of interest in this field.
I don’t think Humanity would have a purpose in the Covenant. It got into space too late compared with everyone else and is hence too weak to offer a significant contribution to the Covenant in order to warrant it’s inclusion into the caste system at number 3 or 4.
Being at the same level as Grunts politically doesn’t necessarily mean the same level of treatment though. It’s been mentioned several times that Humanity’s resolve and strategic acumen was atypical among the Covenant client races, even though they are still largely made redundant by the Sangheili militarily. Humanity also does have a highly organized military and shows some competence that perhaps exceeds all but the Sangheili. In that case Humanity would likely be a special case where the normal rules of the caste don’t apply - weak politically but offered respect and acknowledgment by the higher castes that isn’t usually offered to the lower ones.
That will likely change with time though, as Humanity grows technologically from the Covenant, the highly organised military that it has and the attributes that the Elites noted humans as having might form the basis for eventual elevation and replacement of Grunts and Jackals, but not as canon fodder units (Assigning marines as nothing but cannon fodder would be a waste of their skills that humanity has already developed and that the Covenant can utilize for free). There are forces beyond just the UNSC, like ONI and the Assembly that will likely facilitate that somehow, and we’re an ambitious bunch as well. Perhaps Humanity’s unique offering to the Covenant in time would be the concept that underpins the Spartan programs.
I think that ultimately Humanity has the basis for something that the Elites and the Covenant would find valuable (Which is Humanity’s resolve, strategic/tactical awareness, ambition, military organization and training in principle) but it’s not yet at a level where it would afford them any serious political power. It would take time.