Obviously some of them teach at a high level corps, but when you talk about matching spread across the corps, the students are at a playing level where making a characteristic sound is trivial.
Getting freshman and sophomore kids who have trouble making a good sounds and/or moving and playing is not a recipe for success.
The kids have to feel successful. If you are great at making the students feel successful, you will have wealth in kids that want to be there. AND IN TURN, YOU WILL LOVE BEING THERE WITH YOUR KIDS AND THEY WILL LOVE BEING THERE WITH YOU!!!