At U11 I would put a lot of weight on the coach and environment.
The level of teammates matters because training partners create challenge, but a stronger team with poor development habits is not automatically the better place.
I would compare the weekly experience.
Which coach understands your son? Who gives useful feedback? Where will he play enough? Which environment encourages mistakes and different positions? Where is the challenge appropriate?
A slightly weaker team with an excellent coach can still stretch a player if training is good and the role is demanding.
I would not choose only on league level or results.
At this age, the quality of hundreds of training hours matters more than the status of a Sunday scoreline.
Pick the environment that is most likely to keep him improving and enjoying the work.
