Battletech

Urbies. That’s all you need for mechs if you want a trash rebel force.

Catalyst Labs even leans into this and sells an Urbie box.

Supplement with modern military infantry and vehicles from GHQ.com.

Lore friendly in almost all circumstances. Especially easy to play as some kind of dirt poor mercenary outfit during the succession wars.

“What great house did you buy all these mechs from?”

“Uhhh it no longer exists.”

Engine stalling noises

“You’ve got to put it in ‘H’!”