In 2v2 game as USF/SOV:
1. Build a vehicle
2. Decrew it
3. Let your soviet ally to capture it
4. Enjoy your free SMG squad
PROFIT! 
except the tank is better with a vehicle crew in it because they can get out and repair it and the SMGs cost 70 mun... it does let you easily feed tanks to your ally though.
This sort of thing frequently comes up in balance discussions, but have people considered that abilities/units are balanced within the faction they exist in, rather purely objectively? Whether you think this is a good or bad idea, doesn't it seem plausible for how relic balanced the game?
it sounds like a nice idea.
except that relic's track record is the opposite and even on the soviets it's not a good ability.