I think that once you get to the 4th, it becomes closer and closer to throwing darts at a board. The round doesn't matter nearly as much, and it also doesn't matter with the pay scale. Which is why Les was smart to stockpile 10 picks after round 3.
And, tough guys like Allen have a way of sticking around. I watched some film on the guy (not highlights) and while he CAN be beat on a pass rush, he is hardly a turnstile. And he is just murder in the run game; relentless, twisting, turning his guy just like you'd expect a wrestler to do. Some of that is because he's not all that big. I imagine Kromer will teach him a few things and a year of learning is going to be beneficial for him.
