catholic and C(Population Teams) have a hard time having a large enough roster to enter theses high school only deals.
most Catholic school kids if serious are on one of the club teams(Express), and the C programs don't have the necessary 16/18 kids week after week to play.
IMHO.
Most C programs kids who are serious are also on club teams. And if your HS coach is affiliated with a club team, then he might push his HS players towards that club, and they might make up a decent proportion of that club team.