I also suggested something similar (I suggested about football schools, I don't know if it's the same thing) here in my country there are a lot of football schools and it would be really cool to have that within the game, and adding this to @Rick87 suggestion it would also be incredible to be able to control these teams
Edit: here in my country, most of the football schools for the first division teams are either society (7-a-side football) or futsal, so it wouldn't be possible to replicate it exactly in FM, but it would still be cool.