If a SU player is in need to repair a tank, both the tank and the engineer has to retreat too, same with OKW if you don´t have the T2 Build up (the one with the puma and free repairs)...
and of course, if you want to repair a sherman the sherman has to retreat to a safe spot...
So in the end, all factions has to retreat the tank, and only USF doesn´t need a RE to repair it....
That´s why your argument about field presence is wrong in my opinion, because this happens with any faction, if you want to reapir a tank, that tank has to retreat, not only the OST tanks has to retreat....so this left only the pio squad....come on, if your front line suffers because a pio squad is repairing a tank, your front line will suffer the same with the pio helping there...their figthing capabilities are really low man.....
And yeah, USF tank crews can repair by itself, but the tank cannot attack while being repaired if you use your crew to repair,while an P4 can shoot to targets while the pio is repairing.....and in addition, if you want to capture an abandoned tank as USF, you need to purchase a fresh RE squad for that (or loosing a rifle or other squad to use them as tank crew) while with any other faction, you use your cheaper volvks or pios or whatever and then reinforce the rest of the squad at your base...so USF is in a worse spot in that situation.
so USF tank crews have some advantages, but they have some cons too....and that´s why your arguments are wrong in my opinion and USF tank crews are perfectly fine.
anyway, noob here so only my opinion.
I think you're missing the point about 'manpower' presence. But you're right that the argument applies to every faction, except USF of course, but that's beside the point.
Instead of thinking about it as a pioneer squad, think of it as - the cost of the pio squad could have been applied to something else, a different unit.
Pioneers with flamethrowers are pretty effective. I remember I played a match the other day as USF and the opposing OST was using pio-flamers quite effectively. Needless to say I learned something new that day.
Also, capturing de-crewed vehicles is not any more of a problem for USF than it is for any other faction. In fact, I would say USF is the best at it because they're always able to exit the vehicle and swap with a different crew once in safety, so no units are 'lost' or 'traded'.
USF repair is the best, and I think that's a well known fact. It is one of their faction advantages, after all.
In regards to smoke and blitz - I think it's more an issue of frustration than balance.
With that being said, I do think a re-work of blitz would help alleviate the apparent 'op-ness' of the ability. Some good suggestions already in this thread, the most interesting one IMO was the tank gets a 'engine overheat' after using the blitz. Great idea!!