First of all they will not combine so it is a mute point, but for conversation sake although I agree the bottom end of 5a and 6a is weaker the top end is stronger. 9 of the top 10 teams are either 6a or 5a. Combining those two classes would greatly imbalance the system. I don't know the correct answer except for one state tournament or a grand state. Then you don't have to worry about balance.