It's ridiculous to suggest that the only good hard throwing pitchers are in AAA. Your classification has nothing to do with how good you are, only how big your school is. Now if you think logically there may be more good pitchers in AAA than there is in AA or A, but that is because there are more kids who go to those schools. If you compare 1500 students to 500 students, it only makes since to have a few more talented players out of the 1500 than out of the 500. That's the only difference.
Right of the top of my head, two guys who break 90, not to mention really know how to pitch, in the AA Watauga Conference are John Broyles, Unicoi County, and Brandon Summey from Sullivan North.