Wayman. He would be one of the best players you could add to any college team, any time, no matter what that team needed most. Great skill. Great athleticism. Great teammate. Better person. On top of everything else, Wayman helped make his college teammates better. There should be a statue of Wayman at the main entrance to the LNC.
My 2nd choice of a former player to add the the 2015-16 roster would be Tim McCalister. While not a point guard, he ranks 2nd to Terry Evans on the OU career assists list. He is third on the career steals list. He is third on the career scoring list, even though the 3-point shot was not implemented until his senior season in 1986-87. He was also a good rebounder for a guard, and got to the foul line, ranking 7th all-time for free throws attempted and FTs made by an OU player. Adding Tim McCalister would upgrade the 2015-16 team, as he was a better all-around college basketball player than any of the guards on the current roster.