there's a problem. Your first sentence should have said, "Oh, I thought Cody was faster than 4.65, Ok I was wrong about him. My bad."
If byu actually had above average P5 foot speed, then they wouldn't need such flawless decision speed, coaching calls, etc. Our foot speed would make up for some of the mistakes naturally made in the course of a game. Like top P5 type teams have often been able to do against us when they have less than perfect coaching, decision speed, team speed, etc.
If our players weren't lacking in foot speed and were so good at decision speed and so good at helping create cohesive team speed, you wouldn't have such a dearth of drafted byu players (and active roster byu guys). Scouts would say, man these guys don't lack in foot speed at all and so we can obviously train them in our scheme since they have already shown good decision speed and help create great team speed at byu.
If we weren't lacking in foot speed, then if you lined up all our players by position against against the top teams in the country, we would time faster than many of those teams. But I really doubt we would.
If we don't lack in foot speed then we just happen to really suck at decision speed, team speed, coaching, etc against top 15 teams and just happen to be really good at decision speed, team speed, coaching, etc against teams ranked 75+ in the rankings.