re: Are there transcendent athletes?

I'm with you on every one that you named. Did not see Maravich or Cassanova in college but based on their pro careers and collegiate accomplishments, I don't think you've gone overboard in the least bit. Cannon is probably another. Even without taking into account modern training, nutrition, etc., his "measurables" such as size and speed translate into today's game without any difficulty whatsoever.