Vet 3 lmg obers is the ideal scenario for okw and (most of the time) way later than vet 3 rifle with bars/lmg. Even when you measure max range vet 5 ober + vet 5 volks, 2 vet 3 rifle squads with 1 lmg and 1 bar have more dmg than them. So i dont get your "melt". Combined with their better rec acc they win every engagement where both players have equal cover.
Dont get me wrong. I dont want to have vet5 terminator volks, who beat rifle and sections. I just think that they could use something like -10% rec acc at vet 5 to reduce bleeding. Penals have a similar problem and it gets adjusted in this balance mod.
And about combined arms:
Yeah lets say both players have 4 mainline squads with equal vet and weapon upgrades, a anti tank gun, one tank and one mortar/leig. If both micro at the same lvl the one with the better inf will push most of the time, cause his opponent has to fall back once his frontline units are retreating. And volks are never the better inf in the lategame.
I have seen enough 2vs2 games in the latest tournaments, where okw players struggled heavily to hold ground in the lategame, while mostly providing arty and some at to help his ost mate.
Volks are cheaper, STGs come way sooner than the first bar on rifles. Rifles on the other hand are better scaling albeit expensive (120 for full upgrade + initial bar unlock + can only be acquired in base, unlike STGs and the likes which only need friendly territory). Don't see how you can keep complaining about volks.
If the USF has one AT gun then OKW P4 is more than enough to deal with it. Leig shi** on the USF mortar. USF will most likely have a pak howi (Leig is good vs it with great accuracy and pak howis low agility/survivability).
So let's see your setup USF vs OKW:
4 main line infantry USF -> USF wins most of the time. Only time USF rifles lose vs volks is on long range and before bar upgrades short range vs STGs (since STGs come sooner). All in all, rifles are favorable.
1 tank -> Sherman vs OKW P4. I don't think I have to explain anything here. 234 armour speaks for itself.
1 AT gun -> raketen is more than enough to deal with the Sherman while the AT gun will eat munitions and probably bounce that first autofire shot before the player even pops the piercing shells.
Not to mention that if the USF is constantly using the shells, no munitions for 2x snares not to mention BARs or zooks.
Mortar/Leig: as I have said, USF will most likely have a pak howi which the accurate leig can keep displacing and bleeding. And if you are an active enough player, you can nullify the usefulness of pak. Pak, while being really really strong, it's quite useless vs moving objects. In other words, careful when capping points and careful not to clump units up behind cover.
So if the enemy pushes you this easily with rifles, then it's a L2P issue and not a balance one. Lastly, if the enemy is doing a full scale push with everything, you can always put 2 volks squads behind to flank to kill the pak and AT gun and snare the sherman.
Again, not a balance issue. Volks are fine.