Is this fair?

I am in a Nascar fantasy league with my inlaws. It has a 12 team max to keep it fair. Last year, 2 teams dropped out just before our draft, so 2 other teams took over the dropped teams. Therefore, we had 2 owners that had 2 teams in the league. I think this is unfair, but I went along with it for the year because we all prepared for a 12 team league. Well, draft time is approaching, and I find out that they are not dropping the extra teams. The owners that had 2 teams finished 1st, 3rd, 4th, & 6th. Both teams have never finished higher than 4th in the 12 years we have been doing the league. My questions are, is this fair? And would you still join this league? We have people wanting to join, (although my inlaws want to keep it "in the family" and the people wanting to join are not family). Shouldn't we just drop back to a 10 team league?