I gotta quote D Trump on this, "Sounds good, doesn't work!".
Just today I got myself into this 2v2 match where me lvl 13 OKW with my team m8 lvl 14 OKW vs two allies who i found out were lvl 18. We fought them well and the match went past 20 mins into mid game where my team m8 lost all of his infantry. He simply couldnt keep up with the micro against them. But, i was able to do well and give a solid fight, just need an atleast decent team m8.
Of course there are matches that you can't win no matter how well you play.... even if you would play like a god. But those are around 1 in 20 maybe. In many games it's possible to compensate for unfair matchmaking, for example if you squash the opponent on your side and then flank the other side to help your team.
"Doing alright on your side" is not enough to win an unfair match