I believe that increasing their vision should be enough to make them viable again. Just like what happened with a 3 man Major with a very bad RA. Increasing their vision would work in the favor of USF not requiring vision to spot TWs and be over dependent on Pathfinders or M20 Utility or the weak major. That's about it.
On offensive stats I believe they still lose to Vet 5 volks if they are vet 3 5 man 2xBar squad. Volks still pretty much win.
RE's with superior vision and smoke grenades seems like a touch too much, perhaps lose the smoke grenade if so.
personally find RE's to be OK-ish, could reduce some of the mid-game to late-game impact (weapon racks and decent veterancy bonuses) in favour for more early game impact, like more dmg and cheaper price