Alright buddy there's something very wrong here usf should get some kind of penalty for vehicle crews....firs of all rear echelon doesn't have zero potential,and other factions engineers are not good either...so this point is invalid ( also they have best combat engineers assault engineers).
Second point...wth are you talking about all factions infantry bleed manpower late game....and its not like usf just have rifles u can use combined arms...this was a pathetic reasoning.
3rd point pop cap...first of all usf units have low pop cap even compared to soviets....and lets not forget the cheat man player use to go over upto 135 pop cap.
4th point only medium tanks...so need to have the best medium tanks core in game.....well i agree with you (because bazooka sucks and as well usf at gun) although after this patch with heavy tank nerf ( hard one ) usf have an overpowered medium tank core largely due to free vehicle crew and yet there rumor of pershing and jumbo sherman making appearance...not to mention how good jackson TD is and combine that with doctrinal abilities.
I've told you my reasons for thinking that vehicle crews exist. You may disagree with me, but thats up to you.
1) Other engineers have flamethrowers, letting them vet up fast and obtain bonuses to their repair rate.
2) Rifles are in fact the most heavily bleeding unit in the game. 280 MP, and bars (mid/ close) are their AI upgrade. The combination of high cost with needing to get into close range leads to heavy bleed, especially when facing long range units (obers/ lmg grens/ g43 pfus/ falls). USF has the heaviest manpower bleed lategame, and just about everyone agrees on this point. I will go ahead and disregard the .50 here. Sure, its a great unit, but it is unusable vs. Ostheer because of randes.
3) USF has popcap tied up in its healing unit (ambu) and officers (2 minimum if you have armor). This leads to a fairly large portion of your popcap in non-combat units. Rifles are also high popcap compared to grenadiers, volks, and conscripts.
4) USF has an OP tank base? They have M4A3 and Jackson. M4A3 is only efficient vs. infantry, unless massed and flanking. The Jackson is a great AT unit, but against heavier units (has low DPS and high Pen). The only thing giving USF the ability to retain map presence late in the game is multiple mediums. 1 for the flanks, and the rest supporting your rifles at the main point of contention. USF has no breakthrough tank, so they are heavily reliant on massed infantry to pushe. Vehicle crews are important, because it lets USF armor operate independently of their infantry. If USF had to support all points in the battlefield with infantry (for repairs and capping), they would quickly run out of popcap.