It could also be because in the past Ostheer was at times the monster faction with non-doctrinal elefant, Panzerterminators and Flamer HT at T2.
They started playing with WFA.
Also, Soviets aren't THAT overpowered. The problem is the cheese-units forcing you to play mega-boring strats to counter them. The Soviets aren't auto-win and axis has lots of nice stuff too. It's just the soul-destroying cheese units, which take little micro but force the axis to dance the devil's dance.
Cool way to phrase "soviet stuff stinks except for cheese-units which I hate that are the only way to win"
Your theory about noob-magnet faction is strong. Teammates are a major factor in 2v2. Other theories (and I may be wrong) are he was playing sovs in a bad-for-sovs patch or he was playing drunk a lot or he played sovs when OKW came out and nobody knew what to do about sturmpios. It could be anything. Still, his position tells us he's very good with soviets.
It's more like because 2vs2 (and higher) search is pretty much at a constant 100% axis, if you start searching random as allies, the game will instantly match you to the next guy (who probability wise will be quite low in rank) who joins the queue on allies because the axis guys have been running the search for ages and apparently Relic thinks fast matches are important even when they're utter shit.
Getting high up on the random team game ladders is generally not hard at all, if you just spam games it seems like you always end up going up the ladder now matter how much you win or lose. The ELO rating is pretty damn broken for team games.