By rule, only 2 grad assistants can assist in coaching. Could have 2 defensive guys, 2 offensive guys, or 1 defensive, one offensive. That said, you don't bring a grad assistant in who has never done more than sit the bench as a walk-on QB for his daddy's football team (and couldn't even hack it out there), has tremendous character issues, and 0 experience coaching wide receivers, or coaching in general, really, to coach your wide receivers, while a guy with Lamar Thomas' resume is on your sideline with the headset on during the games.