Plenty of guys have the size, speed and look like players in HS and never amount to much after HS. Then there are others that are football players. Hard work, study film, never give up and are just football smart. Along with all the great shorter stature guys mentioned prior, look up Sam Mills as an example. Walk on at D3 Montclair State in NJ. 5'9" 200lbs .....turned most "football knowitalls"away. CFL then USFL and finally the NFL with Saints and Panthers. Jim Mora said hr was the best football player he ever coached. 3 time All Pro. Still 5"9" but got to 230lbs. It's not only measurables for evaluators.
As impressive a player and more importantly as impressive a man as you will ever meet. RIP Sam