The NFL is a whole different animal, a guy like Mayfield will look good in college but in the NFL he will fail. Their is a reason that you don't see a lot of good QB's in the NFL that are under 6ft. Mayfield was my top ranked QB followed by Darnold, Allen and Falk. Its hard to tell which one of these QB's will succeed in the NFL but having the strongest arm, mobility, size and smarts is a huge advantage vs the speed and complexity of a NFL defense.