re: Inferior teams run 4+ wide sets against LSU defense.

It's a test. By watching how the linebackers, corners, and safety personel react to the players in motion, the qb can get a very good read on whether the defense will be playing a man or a zone after he snaps the ball. This gives him a preview of where the defense will be, helping with timing routes, and whether he should audible to give the ball to someone else since most of those motion plays are options. If the defense is playing man, maybe he habds it off on the jet sweep, but if they're still n sone, he hands it off up the middle or keeps it and throws.