Are Brutes in Halo 4? Everything has lead me to believe that they are not, but then they announce that the Gravity Hammer is back in Campaign (by way of the achievements. It clearly isn’t being held by an Elite when the Sword does just the same, and if a grunt in carrying one I’ll eat my hat.
So are they back?
No! It’s been confirmed.
Hunters dual weild hammer’s now
/sarcasm
but it was rumoured that the Promethean Knights had some sort of grav hammer
Nope!
Confirmed by Frankie 
I’ll sincerely hope a grunt will show up, dual wielding gravity hammers.
> Hunters dual weild hammer’s now
>
> /sarcasm
>
> but it was rumoured that the Promethean Knights had some sort of grav hammer
OK, so I’m guessing Grav Hammers will simply be Promethean-ified.
> I’ll sincerely hope a grunt will show up, dual wielding gravity hammers.
Suicide Grav Hammer Grunts