Go watch some film, he's got a good enough arm
I've watched a ton of Orton, i've broken down tapes. I've done so because I like the guy and want to see him succeed. His arm is not strong enough, its not weak, but its not strong enough to be a high end pocket passer. He has to wind up too much to deliver a deep strike, which takes too long and is inaccurate. That is part of having an arm not strong enough.Arm strength isnt a question of being able to throw the ball 50 yards through the air- there are ten thousand washed out college QBs that can do that. It's about delivering the ball on a rope to a receiver in stride or on his breaks. That requires more than just lofting it far enough, it requires having zip on the ball so it gets there accurately and timely.
Orton's deep balls are inaccurate (he most have missed or underthrown wide open Hester 10 times this season) and don't have zip. You have to be able to make those throws off balance or moving. That's why Brett Favre was a specimen, he could make throws falling down that Orton couldn't make standing along in an empty stadium.
You can beat Orton by collapsing the pocket on him. Do that and he will dump it off, or take the sack. He won't burn you on the go route or find time with his feet. Any QB that can't do one of those two things is not going to be a top 15 NFL QB. Nobody is worried that he's going to take a 2 or 3 step drop and throw it over the defense- he can't do that without setting up, and that's the difference between Tony Romo and Kyle Orton.