It’s not just the crabs. holdbacks are only holdbacks if the kid gets held back. A kid in 9th grade playing for a 8th grade team is not a hold back, it is cheating.
Which teams are doing what you allege?
Whats wrong with that??? It is MD after all . Isnt playing down the norm? Frankly the rules should be if you want to play down a year ( in age) Everyone can regardless of grade ... Would even everything out.