Level 31 teams in level 30 championship

I have just been promoted to level 30 and there are 4 level 31 teams in my championship. How has his happened?
Short version, it happens.

Long version, because the numbers of teams aren't alligned 100% there will be some leagues that have players from two different levels to make up all the leagues equally in number. Promotion and reward levels still line up according to your level. It is unfortunately the luck of the draw and happens to most players at least once.
I have this in my league at lvl 30. This gives the lvl 31 teams an unfair advantage as some players are max'd out with 190 rating against teams that can only have max 185 rating.
Yep, not ideal but it happens. Only way to avoid it is for sublinet to have dummy accounts to fill