Again, the support from individual districts and booster clubs, combined with coaching probably has the greatest impact overall....size of the school doesn't necessarily mean much.
Look at WESCO 4A, overall it is not currently a wrestling hot bed by any means....yet there is plenty of money, numbers (student population), and opportunity floating around....why is it not better?
I could give a long list of small schools (2A or smaller) that would crush almost every school in WESCO 4A in a dual...or many leagues for that matter.
Leagues differ in competitive strength year to year, decade to decade, but the opportunity to be competitive stays the same. This holds true in all classifications for wrestling.
Reality is, a one division state championship would bring what you mentioned...more competition and opportunity....for everyone to have a level playing field (even the "small schools").
Is this what you're referencing, a more "even" playing field? Doesn't get more even than one division for a state championship.