My impression is that Coach Patterson believes that TCU can win with defense-- and a w/l percentage of about 75% over Patterson's tenure would argue that is is right-- and that means he expects his offense to hold on to the ball. Patterson likes time of possession, and no turnovers by the offense, even if that means conservative play calling.
It also means that Patterson will recruit running backs and receivers, and convert them into defensive players.
Apparently if Schultz has a weakness, it is game day play calling. And he may be weak as a play-caller relative to how good he is as a talent-evaluator and a player-developer.
I suggest that, on the whole, he is a damn good coach that deserves more money than TCU can/will pay assistants. I understand that the U of I is somewhat more generous with Zook's assistants, and if so Schultz deserves it.
Schultz has interviewed for several head coaching jobs in the last few years (Rice and New Mexico State come to mind) and always seems to be a finalist but never hired. He's been a TCU assistant at various levels for 11 years now, and maybe it's time for him to broaden his resume if he wants to be a D1A head coach by and by.
Best of luck to the U of I (unless they play us) and Coach Schultz.