Is it Pay to Win?

First of all I'd like to say I've played for years but I'm just getting into the competitive scene. I have a high elo but I keep losing to the same two factions.

The bug faction are so stupid to play against that there's not a reason to actually carry on. I was winning, I had half the map, twice the income, then their Doomux's came along and nothing countered them.

Is there any filter to stop opponents choosing them? Because I win all my games against opponents who play balanced factions.