As previously stated, its more about balance than it is about East/West.
The only consistency in terms of geography is that Districts 1 and 12 are always in the "East" while 7 and 10 are always in the "West". Other than that, the district placements are all over the board for different classifications.
AAAA
East: 1,2,4,11,12
West: 3,6,7,8,9,10
AAA
East: 1,2,4,5,6,8,9,11,12
West: 3,7,10
AA
East: 1,2,3,4,11,12
West: 5,6,8,9,7,10
A
East: 1,2,3,4,6,11,12
West: 5,7,9,10