So I exclusively playing Ostheer, still getting Soviet top 20, meaning what? MVGame
Oh that is quite simple! Its exactly how it was in DoW2 where 80% of players played SM(ost are new SM)!
When you play soviets you're playing against a faction that have much more bad players you're getting matched against, the challenge appears only against german top 50 IF you meet those players, because you will still get matched against average players.
That is obviously a slight exaggeration, but the general idea is something like that.
Balance obviously matters, but not nearly as much as the whiners make it seem, you can see diverse strats and usually better player wins.