Try using a sniper in the Wehr vs American match up, I find that it completely changes the early game dynamic in favour of Wehr.
Anyway I'm iffy about adjusting any sort of infantry at this point. Grenadiers seem competent, for being 40 mp cheaper than Rifles. When you use grenadiers in more of a support role, they tend to do just fine. Trying to go a 3x or 4x gren build against US is just stupid.
Changing riflemen affects the entire game for that faction, although I'd be a-okay with riflemen nerfs if it meant that Rear Echelon Squads and Assault Engineers became more viable. Still, I'm not yet convinced that they're too strong.
As for the halftrack I think you have to be very careful about moving it into t3 because then the only AT option USF has if they go Lieutenant tech is Bazookas. Maybe if you fix their vet 1 vehicle snare this won't be an issue, but I'd be very careful about going crazy on nerfs and changes at this point.
I think you'd be better off toning down the suppression and anti-infantry damage. Bring it more in line with the soviet AA halftrack. Maybe fuck around with it's rotation speeds and acceleration, so it's far less maneuverable and more risky to deploy anywhere near AT.
You don't understand. I'm not building 3-5 grens because they will lose to riflemen 8 out of 10 times. That leaves MGs and sniper. Early sniper has trouble holding territory so MGs is all I have left to defend. Due to MGs inability to target units unless they are near the center of its arc, defending your territory means you must keep your MGs far back (which is why I said Germans usually have to hide in a corner). If I push out, I'm almost guaranteed to get flanked.
Now the sniper is the one redeeming unit the Wehrmacht has vs Americans. However, the fact that it costs 360 MP means I either delay a pak gun for when the deathmachine AA Halftrack comes out ~ 7 min, or forgo the sniper to get the pak out on time. The sniper also needs to have constant defense - grenadier screening with faust and MGs to stop rifle rushes - further cementing the role of defending a small piece of territory. Now this strategy might not be the end of the wold, but half of the maps make a defense strategy very hard to pull off and only a couple actually favor it. Maybe if I didn't have to face an unstoppable anti everything vehicle 7 min in the game I could get more units to deal with his superior infantry, but I can't since I need an AT gun.
If the Halftrack was with the captain, that means I wouldn't have to face the very anti-infantry potent lieutenant as well as the Halftrack. If they want to go Halftrack, they build the captain, meaning I have more time to prepare for this ridiculously strong vehicle and also have an easier time dealing with the AT focused Captain.
Soviet t1 doesn't have hard AT - the building is purely for anti infantry and utility. The same should be for Americans - where the lieut, car, and MG can provide light AT but mostly provide anti infantry support. It shouldn't be a tier in which you can counter anything the germans can get.