I also think USF are pretty good, just need proper indirect fire at all stages of the game and more durable armour in the late game.
Pershing and Calliope I would love to see but I don't feel they are the solution to USF balance problems, but that's all in my previous posts.
consider it a part of a solution then because USF needs new hardware NO MORE hand-me-down quality equipment it needs to be top of the line just like the brits in order to survive late game
The KV-1 isn't a Heavy Tank by gameplay standards. While it's slow, it doesn't have 1040+ health or a powerful multipurpose main gun like the Tiger I, Tiger II, or IS-2.
Guess I'm eating my words. At this point though, I don't think the Pershing will be all of that much use to the USF. Axis still have plenty of creative players that can figure out a way to deal with it.
The biggest worry I have about that doctrine will be the Rangers. :<