I guess I'll be the one to ask it then, how would this be balanced at all? Forgive me if I am wrong but the m2 does more damage, and suppression than the mg42, and maxim. Riflemen possess smoke and american early game is already good. What would be able to stop the best core inf in the game combined with the best machine gun team in the game right from the start? I've read in a few places that I am not the only one that thinks the 50 cal is the best mg. Americans would be able to just shut out axis like axis could with kubels. And before you fanboys start saying "It deserves to be that way cuz kubels were OP" let me tell you making something imbalanced for the other faction does nothing but satisfy your childish spite.
First off, the US early game is shit, no variety and easily countered. Secondly, adding another unit to the barracks would help spice things up with the US. While I don't think an mg would be a good unit to add to the barracks, I doubt it would overpowered.