Rangers trade well at all levels if they are upgraded with thompsons.
Lmgs are standard for usf nowdays, so yes i would balance them around lmgs, you wouldnt balance grens without thinking about lmgs?
There is no need to close the gap with lmg rifles. At vet 3 they can do it easily tho.
Usf without docs doesnt work, just like sov.
You should never balance around doctrines, plain and simple. I suppose we should nerf Ostheer late game because Ostruppen provide an even stronger early game then some factions?
Also trading isn't exactly what rangers accomplish. Yes they should take thompsons, but that means they only rip squads apart close range. That means that they have to approach and potentially lose models. Then, when they get close, a smart player would just retreat or move back as not to get ripped in half. That's not trading so much as taking casualties to force a retreat and win engagements.
Which that last sentence sums up USF in a nutshell.