Balance is a delicate thing. It doesn't take much to knock a unit (or faction) off the peg one way or the other.
Toning down USF needs to be done with care.
With Riflemen, we've got two options:
- Riflemen are pretty meh, with the 200 MP Officer power spike making up the difference. This is what we had before, and USF play became about building as few Rifles as you could get away with.
- Riflemen are good, and the Officer power spike is toned down accordingly.
Currently we have good Riflemen
and the Officer power spike, which is a bit much. Cranking up the manpower on the Officer as you suggest tones down the power spike, but it also messes up the USF tech structure.
One possible solution is to make the Officer unit only worth 200 MP, then give it an upgrade that cranks it back up to its 300 MP power level.
Similarly, any changes to USF fuel income will mess up its carefully timed tech tree and undermine the teching rework.
The M20's a simple fix though: ditch the bazooka. That tier has the Lieutenant bazooka, .50 cal AP and the Stuart. It doesn't need an AT vehicle crew too.