Edit:
So what do you specifically don't like about them exactly, I'm curious. I mean you can see our opinions about the UKF above, as for the USF I personally think that they should get heavier armored tanks in order to go toe to toe with the German heavies, an M4A3A2 Sherman Jumbo would be nice to act as a meatshield for Jacksons and overall be a breakthrough tank for the USF which would not be limited to only 1 like the M26 Pershing, another 2 additions which I would like to see are the M36B1 Slugger which was based on the Sherman hull but still retained it's Jackson turret and 90mm gun, and a Sherman Crocodile, as an alternative to the 105 Sherman.
And I really do think that the Calliope and Crocodile, if ever added, should be able to fire their main weapons like in real life with a toggle, similar to the KV-8. For the Calliope it could on a bit longer timer so you can't instantly switch into artillery mode and fire in a split second.
Riflemen are too expensive for their capabilities, reduce cost to that of volks or buff them a little bit. Having access to 2xBAR is not an argument for their high cost because that requires a ton of muni and it also requires teching. They only outshoot Volks at point blank, right where Volks have early access to incendiary, their moving accuracy is really not a significant item at .6 when volks are .5 and just sandbag, where you lose a rifleman if you close, Volks are effectively better core infantry at cheaper cost in a faction with a non fucky teching order. I think it would make more sense to buff them in some way instead of cost reduction and further avoid more homogenization of the game, maybe buff moving accuracy to something actually significant like .9 or higher DPS at mid range. Buff the Stuart or give it a cost reduction. All the other stuff is fine. I think the teching structure of USF is retarded but I don't have any good ideas of how to fix/improve that.