As some of you know, I live near Arkansas State University. One of the first things Butch Jones did when he became coach here was institute a policy to always tuck in shirts for players and coaches. This was an Alabama policy under Saban.
A coach I know turned down a job at Vandy partly based on the similiar policy by Coach Lea. His understanding was coaches at Vandy were required to wear collared shirts and slacks in office and have shirts tucked at all times around the program.
I get the discipline aspect, but at the end of the day tucking your shirt does not win ballgames.