OKW actually have stopped being designed around FRP the moment they were allowed to build trucks on base sector without the need to create resource chain.
USF, well, it exists for sole purpose of excusing Majors and ambulances existence.
Yes, but remove it and you simply reverse the situation:
Ostheer can field 1 ht reinforcing in any territories + 2 bunkers heal/reinforcement
Sov has T3 ht reinforcing in any territories + merge if they want to keep a support weapon on field and retreat a cons.
OKW and USF would simply be pushed of the map too easily. Early game for OWK since they have their T3 to temporize around 10 minutes but USF would be pointless with only rifle and HMGlolriflenadeinyouface/HMGlolflamnadeinyourface.