Good machine gun placement is usually the key. Most OKW infantry don't have anything to negate machine guns, i.e. smoke grenades, so they have to either find some way to flank the position, or hammer it with indirect fire.
As long as you are constantly displacing your crews, you shouldn't have too many problems.
Then you have the cheesy units that appear in buildings behind your lines and kill in 5 seconds all the crew of your support weapons without a chance to retreat because the guy pulling the weapon is always the first to die...
Currently, as soviet, T1 doesn't give any unit that can survive to midgame, and T2 means maxim spam.
Nerfing maxim will mean that OKW will win easily against Soviets only blobbing infantry.