PP here. I think there are a lot of age based systems that work, the issue here is not that there are not good age based systems we could play under, it is that the leagues, clubs and tournament sponsors (and assume high schools) push/allow a grade based system. How do we change that? I assume it would start with getting HoCo to change its' policies but it appears the league is effectively run by the clubs so back to square one.
It wasn't that long ago that we were playing in an age based system, seemed to work fine. As the other poster said as well there are lots (if not the vast majority) of club youth sports that play under age based systems and they seem to be doing fine.
I really like the idea of grade with a max number of pre 9/1 birthdays, that would seem to be a decent compromise.