My opinion: this is a championship. You don’t get special matchmaking cos you’re not as good. You get put in a division, and you play all the teams in that division. The teams at the top of the premier league/nba don’t just skip out the teams at the bottom. This matchmaking should have started out as being random within your division. I invested in my roster better than 95% of players, but I’m playing that top 5% so my advantage is cancelled out. Where is my reward for being better than most?
That said, in the case of this game, after a while of records being established, your record should be factored in (but not solely relied on), so it can be decided who is best/who is middle/who is worst, rather than the top players beating the bottom players every time. When my record is amazing, I should get a group with 1 or 2 really strong players, for it to be competitive, and be above the rest. Before that I should be dominating.