IS to me aren't an issue. Early game you will see 2 normally with them going a vickers and rushing tier 1 for early engi or AEC (A different issue). The rifleman horde is tough and I agree the Ostheer need something to assist. I don't think it needed to be addressed by giving the MG42 in T0 though. Would of loved to of seen a different approach.
In my mind, the solution would be to put some kind of manpower wall in front of building riflemen in the early game to delay how quickly the USF player can get them. The Ostheer does this with production buildings, maybe putting the riflemen in the Lieutenant tree and lowering it's manpower cost? This is looking at it from a somewhat linear viewpoint (I play way too much brits and wehr), so I'm not sure how this would affect early game captain play.
Only problem is that either stormpioneers or Ass grens could utterly screw with USF early game, although considering how long usf has stomped in the early game I would like to see it at least once.