Something that you don't realize that, IMO, is that while vet3 terminator vet is an issue, most units can safely roam in a blob against other small arm fire units late game due to abundant yellow cover. This affects all units and makes teamgames go into the realm of blobs of infantry, artillery and tank spam.
#Nerfcraterbonuses
Teamgames aside, isn't the whole point of MG's to be able to handle inf blobs? Its part of the reason why giving USF a (non shit) mortar doesn't work, as it removes axis's only effective tool for dealing with massed inf. The issue right now with USF is that they can blob with no penalty and OKW/Ost don't really have an answer to that as they can't really use mg's with turbo mortar, their inf gets melted without supp, and the stuart kinda shits on anthing that they can bring out (444 and Puma aside).
So (for example) if the USF player goes 3 inf 1 mortar + cap + stuart, OKW/Ost doesn't really have a good answer to dealing with it. In particular OKW struggles because they don't have a good AT solution to deal with the Stuart outside of the Puma (which is quite fragile against the Stuart's stun rounds), and going Puma means that they will have a very difficult time dealing with USF's infantry (because Puma is forced to have shitty AI, lest it takes over the role of the Luchs in the same building). As the game matures into the lategame (of/c assuming it gets that far), regardless of whether OKW went for the Luchs (to deal with inf) or the Puma (to deal with the stuart), they still can't use support weapons to compensate ( MG is not that great and useless due to mortar, raketten is garbage, leig is ineffective at just about everything it does + its in the medic truck which has no at solution, or even that great of an AI solution since the Luchs was taken out of it forever ago). So in the endgame they are stuck with fragile expensive inf paired with impotent volks and sturms against a chunky inf army that they don't have the tools to deal with outside of scavenge doct (which is still only a patchwork solution).
Ost is stuck in a similarly poor position with their MG being useless and not really having a good light vehicle counter. However my ost play is significantly weaker than my OKW play so I don't feel as confident explaining their issues. In particular my sniper play is trash so I can't speak to its efficacy at higher levels of play.
Really the solution (to me atleast) seems to be to nerf one of the following components: USF lategame tankiness / USF mortar / Stuart. The USF mortar currently hard counters Ost and OKW's answers to inf blobs, and the general chubbiness of vetted USF inf allows them to deal with elite inf with relative ease when they enter the field. The stuart is borderline abusive in its role due to its excellent AT (due to abilities) and decent AI. By reducing the chubbiness of USF inf in the late game, it allows elite axis inf to be actually able to deal with USF blobs when used in conjunction with volks.
Now preferably the USF mortar should be nerfed into being a very niche unit (to deal with mg spam) or removed altogether, but that wont happen. Nerfing the Stuart only is a patchwork solution and it would be hard to make it as relevant in the future without just buffing it back closer to its current state. Truth to be told I'm not sure how one would effectively nerf USF vet 3 beyond just reducing its effects to certain circumstances (only works when standing still, or not in green/medium cover), but then again I'm not in the top 200 so I think I can get a little leeway there.