I'm just a simple accountant, but I think second string goes to at least 44. So you'd even have 9 3rd stringers
(but no the original idea is very weird and bad idea).
I just peaked on Naz's max prep page out of curiosity. It's pretty messy and obviously self reported, but it seems like a normal year might be mid 60s, maybe up to low 70s in good years? But yea, don't see much benefit from cutting kid 54-70 in terms of balance. Those kids are at that school because that's where they/thier parents want an education. They aren't being held away from their local public school that needs help balancing the sports talent scales.
I *think* CCL does use football participant numbers in their own division classification though. By all means, IHSA should ask them and find out more about that concept and how it's applied.