From what I can tell at my meager skill level, Soviet infantry simply cannot compete late-game with the Germans in cost effectiveness. The reason? Upgrades may be limited in the early game such that you can focus-fire the LMG or G43 or avoid that squad. But since the upgrades are one time costs, and there's no reason whatsoever to avoid upgrading to LMGs (you always want to be still behind cover anyway) and G43s, you end up with every single squad of grenadiers upgraded fully by the endgame- and their reinforce cost remains exactly the same at 30MP per man. At that point, Soviet non-doctrinal infantry are outclassed by grenadiers with one upgrade, stand no chance against grenadiers with two upgrades, and the soviet player has to accept extreme manpower bleed to force a squad off the field if it's positioned properly. Grenadiers with double upgrades are simply untouchable unless caught with their pants down.
Currently, the best ways to win the infantry/manpower war are 1. Armor 2. Indirect fire and 3. Squad wipers.
You'll have armor parity against an equal player, so devoting tanks to pure anti-infantry won't work (or if they're an elite troops player they can pull an Ace out of their arse for manpower and win the armor game if they're even with you before).
Relying on indirect fire/squad wipers is just RNG and honestly nobody really likes it. Germans hate it when mines or mortar shells or KV8/IS2s wipe their squads in one go, for good reason, and relying on mortars and mines to one shot is frustrating for Soviets when it doesn't happen. Snipers are probably the best bet, but they don't work on close quarter maps well enough.
There are a couple possible solutions: 1. Weapon upgrades for Soviets 2. Direct nerf to LMG and G43 3. Increase manpower/lower reinforce/lower upkeep for soviets lategame so they can afford the bleed 4. Veterancy buff for Soviets.
1. It's been suggested many times and not been added. Most likely it will never happen outside a commander, which doesn't solve the problem. Also symmetrical upgrades for both factions is dull.
2. Balancing the LMG AND the G43 will be difficult, since they both stack.
3. Hard to balance right
4. I prefer this option actually- if the Soviets get better vet than the Germans, lategame vet 3 conscripts/penals can trade evenly with LMG grens even at full vet. Comebacks due to losing vetted squads would be difficult, like with Americans in Vcoh, but since you vet faster by shooting vetted squads it shouldn't be a killer.
So to conclude what I'd suggest
1. Give G43 and LMG different niches, and
make upgrades mutually exclusive so balancing infantry for commanders with and without G43s is possible
2. Move Soviet vet 2 and 3 stat buffs or vet 1 and 2, and
give vet 3 a large bonus to health/accuracy
3.
Reduce squad wiping options for Soviets, it's annoying for both sides.
Thoughts? Tell me I'm right, wrong, whatever you want