Germans are good at holding a little piece of land, the majority of any big map usually belongs to soviet in the early game.
You say that a 3+ mg opening forces scout cars, meaning that you force a general tech route, that you can predict it, thus usually counter it.
I agree with the theory yea, but after the scout cars, the soviet has no Need, nor is he Pressed or Forced, to go su85. They usually do that all on they own.
Also, the popularity and threat of clown car openings, cut into the use of the mg42, I went 4 grenadiers for a long time because of it. Now ill go 2 Mg's and 3 grenadiers. And I usually Still need to up gun my scout car in tier 2.
So. Clown cars are forcing Germans into a tech route just as much. Thus doing the exact same thing you claim that makes Germans OP.
Also your play is cheesy and can be hard countered by a cheesy clown car build.