Man, it is a ladder(!). You get paired with anyone who has "as good record" as you do. Yes, their record is bad because they do not play actively. But your rank is still same.
Problem is that some play differently than you do. You try your best some just twiddle around with their rosters. But still as a ladder some teams got better players. its like having Michael Jordan playing in the back yards and he really would dominate everyone. There are no rewards being super good in those games so he wouldnt do that. SWGOH has rewards so it is useful to bring him.
I imagine that MJ wouldnt have to sweat on those games (6 GLs) versus you (few GLs). Just hope that he has "not in the mood today to play".
It is NOT supposed to be fair. You bring whatever you can and try to win with those anyone who happens to have same rank. Problem is that we have almost 10 years of rosters and some do not want to play NBA but just hang around in the local courts instead. Its their right.
You win -> You get higher.
You lose -> you move down.
Simple.