There are actually 3 high school fall leagues the 2 you mentioned and also at Holston.......
I am familiar with Powell and Holston and have heard about Anderson....
I guess the best people to contact would be Head Coaches even though they don't coach they would have the info......
such as George Hall(Knox Halls)
Knox Centrals(Cox), Gibbs(Carol Mitchel), (Coach England) William Blount....actually any of the AAA-AA schools around Knoxville would know......sorry that I can't give you more specifics....