Other than the obvious, QB. I would think that somewhere on the line. Recievers and Backs are given routes, patterns or gaps but the line has to be prepared to make a decision quickly on changing asaignments if they get it wrong the play is blown.
There are so many things a center and a quarterback have to read and react to quickly.
The NFL game is an entirely different beast. Peyton Manning is making a hundred decisions before the ball is even snapped.
Often a college qb has a few keys and a primary read with 2 progressions. Still they will usually have to be able to check out of plays that are bad and get into plays that are good. Not easy.
Often the center is reading the 7/8 guys in the box and making the protection calls. Not an easy job either.
HOWEVER HH: It is often taylor making the protection calls to the line if you didn't notice. So he's doing the job of the center AND the QB. So dumb, I know