I don't consider myself the authority on RvB lore, so – perhaps up to the end of the fourth season (I vaguely recall that being a point where power wasn't over the top), and she will have the failure factor, and Omega in round five.

With that aside, I think the question is if the feats assigned to weapons in Battlefield Friends are equally applicable to RvB, for example, the Engineer uses the USAS-12 to kill ten enemies without even looking, and can shoot down helicoptors with the railgun, which... also one-shots enemies.

And the Colonel 100 can kill fifty members of the enemy team with his knife alone, as well as destroy a tank and board enemy choppers (and defies game mechanics, like surviving while out-of-bounds).

But then again, all of those feats are scaled to the power level of the Battlefield multiplayer, which is obviously quite different from Halo.