There is a lot to like about Glennon. Tall, big arm, can make all the throws, etc. his issue is his bad feet and struggling getting laterally. His bad feet allows defenders to catch up on a route. He is a classic statue Coryell QB that if given the time will tear you apart. He gets flat footed in the pocket on any occasions which makes him throw down and low to receivers.
Glennon has the tools but he has God given limitations that will be hard to overcome. Not to mention he won't be coming to KC since he is not a WCO type QB.