Let's take a look at the location of the 16 teams that played for state championships.
II-AAA Brentwood and Chattanooga
II-AA Knoxville and Cordova
II-A Nashville and Collierville
I-AAAAA Smyrna and Brentwood
I-AAAA Maryville and Nashville
I-AAA Knoxville and Nashville
I-AA Alcoa and Madison
I-A Jackson and Lebanon
The winners are listed 1st on this list. I agree that it is impressive to have 4 teams winning from the Knoxville area, but I would not say the east is dominating Tennessee football and I live right in the middle of Region I and my high school plays in Region II.