I don’t have any kids so I’m not sure what I would do with a kid who was really gung-ho about sports, esp football. You don’t want your kid to be a weakling, no matter how smart he is, right? Athletics are important in the learning process.
That’s why sports in my opinion shouldn’t be a part of school, except for “phys ed,” i.e., running, jumping, low-contact stuff. If parents have to take the responsibility of forming and participating in leagues with their kids it’s on them if the kids start getting hurt.
But I don’t really know. If I had a kid and he was good at sports and wanted to play football, I would feel like a crud for stopping him. (Or trying to get him to play soccer instead.)
If a boy has the athletic to play in college, waiting until being a sophomore in high school is not going to hold him back. Flag football is great for developing talent, for skill positions. 7 on 7 football is widely played for passers, receivers, backs, LBS, and defensive backs.