Play US then.
Guards are your LMG Grenadiers
Requires 2cp, costs 120mp and 15 munitions more, and has a balanced hand grenade instead of an insta-win rifle grenade.
You guys complain about T-34 "spam". If Guards are the closest we have to competing with LMG Grens/Obers, there's your reason.
Changing Soviets to have core infantry unit that scales into late game would require complete faction re design.
lolwut? why is that? can you give me a reason, or is this just some slippery slope argument you keep throwing out there and hoping it sticks?
Giving PPSH as a non doctrinal upgrade or doing something to Conscripts will tweak balance completely in Soviet favor and brake it completely.
LOL. Yes, we can't have those conscripts doing anything past 5 minutes, it would ruin the game!
Let's ignore the fact that LMG grens are superior to everything except 2x M1919 Riflemen, and even then an accurate rifle grenade will win that fight for you.
Oh, and they cost as much as a Conscript (less if you take into the molotov/at nade that Soviet have to pay for, when OH get faust and rifle nade for free)