I have clues about the numbers, just not which they would use. There would be appear to be three options in Division I, after a complete split. These are for football schools only, some of the problem has been with dividing by all schools whether they have football or not.
3 Classes-96, 96, 96
Class A to Lewis County at 587 (1A/2A playoff break at Halls, 395)
Class AA to Hardin County at 1123 (3A/4A playoff break at East Ridge, 829)
Class AAA to Blackman at 2381 (5A/6A playoff break at Maryville, 1445)
4 Classes-72, 72, 72, 72
Class A to Scotts Hill at 502
Class AA to East Ridge at 829
Class AAA to Beech at 1297
Class AAAA to Blackman at 2381
5 Classes-58, 58, 58, 57, 57
Class A to Hampton at 429
Class AA to York at 669
Class AAA to Sequoyah at 955
Class AAAA to Gallatin at 1381
Class AAA to Blackman at 2381
There would probably be issues with each. Three class/six playoff classes, you have the same trouble with some teams not wanting to be in a regular season district with teams in a larger playoff class-even if it's not that much larger for most. You'd also probably still have the formula being used since a region might have two 1A teams and five from 2A playoffs, for example.
Four classes is what I'd go with. Still, 72 teams divided into 16 districts makes for small groups, and divided into 8 leaves very little room for outside the region rivalry games.
Five classes would probably work best if not for the travel for some teams with some regions spread out really wide.
Division II, I'd let those teams basically work out their own classes. Ensworth, BA, would play at the higher level so the smaller schools wouldn't have to worry about facing them. A cutoff at 500 might put Lipscomb in with the big dogs, but if the division as a whole feels it's better for them to play small, then raise the cutoff or just judge each school individually.