On several teams every player wears a quarterback-style sleeve that needs to be consulted on every pitch, both for offense and defense. Why? College players aren't smart enough to remember the signs?
Because opposing college coaches and players are so good at stealing signs.
They can call out a number and it means something, then never need to use that same number during a game. You can change signals around every day if you want and never have to worry that a player will be confused.
Baseball has been using signs for over a hundred years, and with some very serious money at stake they could afford to have some dedicated sign stealers on their staff. Yet they apparently don't have a problem. Are the SB coaches just paranoid?