"Machineguns, Machineguns, Machineguns"
3 well-coordinated MG42 destroy every infantry heavy strat. Use attack move (Hotkey: A) every time you move an mg and use pios or grens to support. I normally go: T1 = Gren, 2x MG's, Gren, MG Grens cap and take on suppressed Cons, while supported by two of the MG's.
The other one is gonna protect a fuel point. Go for FHT to burn the bolsheviks. Massive cons mean at-nades and molotov-spam, but ppsh spam needs a lot of ammo. Still be carefull.
Change MG positions always and katyushas have limited effect. Build 2 paks to deal with T3 before you get a tank or 3 if he denies you fuel, or if you know he is going for T4.
MG's always need to support each other to avoid flanking.
For late game use Ostwind or Brummbär. Brummi is useful against T3, too, because of it's aoe and stun ability, both regular shots and target weak point, giving paks free shots.
NEVER LOSE THE INITIATIVE! Flank, use MG's aggressive and show him you are not feared of his red hordes. Also use the incendiary rounds of the MG's.
