Ignoring the Vehicons since that's their primary role, are there any figures that could work as a generic Autobot or Decepticon for background purposes?
Given that they aren't actual G1 I suppose Offroad, Alpha Bravo, and Rook from CW could work though, for me, those sculpts have so much personality that they stand out regardless.
Hmmm...well there are the Omnicons from the Energon line if you're looking for Autobots. Edit: Just remembered the Scrapmetal from Cybertron could work well for Decepticons.
Holy crap! How could I have forgotten the Energon generics?? Then again, it is the Energon series so....
I've troop built Movie Terradive and Space Case - they make good guards with the lance weapons (and they don't really look like any other characters on my shelves). Energon Sharkticon works, too, as a mass force type character. The U2.0 voyager and ultra figures also contain a number of options - Tread Bolt (especially if you replaced Classics Jetfire w/the T30 Leader), Dropshot, Stormcloud
I remember a while back it was suggested to use the retail overflow of Bumblebees as troop builders, but let's be honest, they stand out. Troopers need to be both uniform and nondescript. You could reasonably do it with a bunch of Dark of the Moon Crankcases or Crowbars, for instance. They're both so bland and generic in both forms. Hatchet a little less so unless you want a pack of robo dogs.
Actually, if Stinger from AoE was any indication, Bumblebee lookalike generics are now a thing. Plus, you can totally get away with having a swarm of Bumblebees! No, I'm not sorry.
T30 Crosscut has a good look going for him for "filler". Plus as far as cannon goes you can always troop build: The Legends Class Insecticons TR Gnaw TR Scourge T30 Tankor The Energon Terrorcons Any Junkion Toy Cybertron Blurr A Rainbow of Seekers (there's KOs of the classics mold in every color you can imagine as well as some extensive official options) I think that CW Blast Off has a good "Air Trooper" look with CW Alpha Bravo probably matching him best for the Autobot side. Other than that I'm not sure.
Combiner Wars Blackjack makes for a good generic, plus he's based of the Battlechargers design which was also used as generics in Devastation.
