I actually can't believe what I just read there...
You must be the first and only person I have ever come across to say that blobbing grenadiers is an effective tactic vs the USF? I mean wow. Double bars will out DPS grens at any distance not to mention the fact they fire on the move.
I also have no idea what your talking about with the 5 man squad formation. I think we must be playing a different game as a unit with smoke, AT nade, customizable weapon, and easy vet combined with the majors fall back is ridiculously good vs fucking Grens.
The issue of USF indirect fire is indeed a problem and not one the OP even addressed. The pak howie is near useless and the mortar halftrak hardly justifies it's cost. However I usually deal with paks the same way I deal with anything as the USF: just smoke and mow it down with your insanely awesome infantry. The Ostheer faction naturally suffers from late game AI unless your already facing tigers in which case the game is likely already over.
But yes the 57mm is terrible and needs a look along with some serious buffs to the pack howie.
Don't worry, I'm the second person.