Murray's height is irrelevant. His speed will be far less evident in the NFL. The only thing that matters is the speed of what resides between his ears. That's the million dollar question, far more than any physical pros or cons.
Can he instantly diagnose and process a defense? Will he sit up nights and weekends all hours of every day with X's and O's, game planning and testing and thinking and working with coaches?? Will he become a mental master of the game - a tireless leader and communicator of those thoughts - the true hallmark of the overall greats?
I want Tom Brady or Drew Brees or Peyton Manning back there. Not because they are tall or short or fast or slow or black or white. Because they are football savants, who are relentless in the pursuit of mental mastery of their craft.
I have never met Kyler Murray. I have only seen interviews, tape, read articles and heard the insights of those who have, and I question this aspect of Murray's makeup. His physical attributes outside of being short are beyond any reproach. He's the best athlete of any QB since Vick, but if that becomes important to your QB's game, it's a losing proposition.
If he has the whole package according to those who make these decisions, then he's worthy of the #1 pick. If he's a physical specimen who can't master the vastly more complex NFL mindcraft, he's our own Jamarcus Russell.