This isn't something people usually like to acknowledge with the Tall vs Short debate with QBs because I think everyone wants it to be cut-and-dried, simple. Tall good. Short bad. A clean story.
But there are also advantages to being short. And there are disadvantages to being tall.
I saw on one of Jon Gruden's QB School videos I think with Brock Osweiler he pointed this out and it's so true. He said you're tall, you love being able to see over the line and see the defenders, and that's great, but you know what? The defenders see YOU too, BECAUSE you're so tall. It puts so much more importance on your face fundamentals, disguising your intentions, drawing the coverage away with your eyes, having great timing and getting the ball out.
It also puts a surprising pressure on you to keep your feet active and get to those passing lanes, because tall release or not, you're a big sight back there for those DLs and they're going to see what you're doing and see you swinging those levers in time to try and get their hands up.
Small guy sitting back there behind a mess of big lineman, you can criticize him and say he doesn't see the field (which may be true of some, not true of others), but the field also isn't seeing him all that well either. That's why it can be so hard for DLs to contain him. And it's one reason you might be surprise just how FEW passes he gets batted down by linemen.
What I think Nick Saban's defense did so well, at least for the first couple of drives, was predict some of those passing lanes particularly on quick slants, as the coverage was baiting them, and then they went ahead and floated linebackers into those lanes to knock it down or threaten to intercept the ball.
But even that had its limitations. Defensive ends get lazy about staying disciplined in those passing lanes. Kyler Murray converted a key 3rd down against Bama by hitting a quick slant because Buggs didn't feel like babysitting the passing lane, was a little too tired, and a little too aggressive. Very next play was the 1st down HOLY COW pass under pressure deep down the field into the end zone.