IMO, league teams are not chosen by quality. If you have a team full of 9* players, 99% chance you will be the only one with 9* players in the whole league. The rest will be 3* 4* and a few 5*.
Well anyone can play anyway they want. If they wanna win with a team of 9*, sure. But where's the fun?
If that's the case then yes, I'd agree with you, that it's probably more fun to try and win against opponents of a similar level.
FC Bristbury
Season 5, Level 5
League Winners Levels: 1, 2, 3 & 4
Champions League Winners Levels 2 & 3 Double X 2 (League and Champions League), Levels: 2 & 3