I'm sure some teams tried double teaming Donald. If he had penetrated and made stops behind the line against just one or two teams, I might say he was just facing a bad player or a bad offensive line... but the guy literally made plays against every single offense he faced. There wasn't a player, a combination of players, an offensive system, offensive line coach, or a gameplan that was able keep Donald out of their backfield. He created problems and gave nightmares to every single team he faced, no matter what they did or what they tried to do against him. He was the single most dominant defensive tackle I've seen since N. Suh, and there wasn't a player that was even close to those two. As much as I loved Richardson last year and thought he would have been perfect in Dallas, he had few plays in his career that rivaled what Donald did on a regular basis.
I realize I have a man-crush on him, but Donald is a natural DT who plays like a man possessed on every snap of every game. If he's there for Dallas, I will be beyond thrilled, and the Cowboys will be well on their way to having a dominant 43 defense. What a truly dominant 3-tech does for a 43 defense like we run is greater than just adding some sacks or tackles behind the line. It changes everything on defense. Take Sapp away from that Tampa defense of the early 2000's, and you have a completely different defense. Rice, Brooks, Lynch, etc. were all great players, but I think they could have won despite losing any one of them. Sapp was the one guy that they couldn't have won without, because that position is so vital to a 43.
Donald would be a terrific addition if he's there.