On the face of it Williams is the perfect fit for the offense that North Carolina likes to run. He is a big physical quarterback who can run with power, and do it really well. This offense doesn't call for the quarterback to be the power back, but if the QB can add that element it does make the offense more dangerous. Williams does that, and then some.
But he isn't just an athlete playing quarterback, he can spin it. The biggest issue for him is his decision making. Far too often he tries to make the spectacular play when the simple one will do just fine. All quarterbacks suffer from this affliction, to one degree or another but it is really glaring for Williams.
Since taking over for the injured Brynn Renner starting in the North Carolina State game his efficiency numbers have gone on a steady downward trajectory. His QB rating is 146 for the year, but outside of the 80-20 pasting of an Old Dominion squad that is transitioning to the FBS Williams rating hasn't topped 127 since late October. Its the same story with his yards per completion number; outside of the game against an overmatched ODU squad he hasn't topped 7 yards per attempt since the Miami game. You expect anyones efficiency to go down when they transition from a role as a spot quarterback to the quarterback, but not really to the degree that William's numbers have.
Williams is a huge part of the Tar Heels offense, and he will be a great quarterback one day. But there are moments in every game where his youth is really showing. On the list of things that Art Kaufman can live with, Marquise Williams throwing the ball is probably near the top. The hope is to contain him on the ground with the Bearcats defensive line, keep him in the pocket and force him to make tough throws, into tight windows. That might not be a club that he has in his bag this year.