70 ammo becouse compare to other tanks 50cal on a sherman is much much better than mg42 or mg34 for an axis tanks. USF ammo design is fine.
Ambulance has a high pop cap becouse it's a moving healing replacing platform. It's fine.
USF early-mid game is perfectly fine. I wouldn't cry about it. AA HT supported with riflemen can stand the pz2. It won't win but if you don't make any stupid move you shouldn't loose it until you get zooks or maybe captain tier and AT gun.
Problem is a USF late game (especially in a teamgames) where there is no point even getting any of those paper tanks.
70 ammo cost M20 Armor upgrade But seems like you more a writer than a reader
Paper tank?
There are some - thing that allows to axis to dive successfully
Reallly bad Rifle antitak nade time and desin of it (req vet 1 ability)
Second Smoke on some axis tank.
THird extended vision on infantry (Voks veterancy)
Sherman by itself is OK
Jackson misses too much at long range and very clumsy itself + have slow turret rotation.
Thats it.
ps P47 doesn't work vs mediums
And MOST IMPORTANT PART USF HAS NO AT GUN