If you play press man, take the inside shoulder and run the WR up the sidelines, what happens when it's a run? You're already in full sprint mode away from the play. Conversely, if it's a run play and you're in off coverage, the WR has to run block, can't get hands on you right away, and you can crash top down towards the RB. I mean, there are inherent weaknesses in all coverage shells, and that's why offensive coordinators try to exploit those weaknesses with what typically works at the time. In the meantime, defensive coordinators are constantly making in-game adjustments to what they think the OC is gonna do and vice-versa. It's a chess match. Williams shows blitz just as much as he actually does blitz too. That forces a quick decision by the QB who didn't really have to make one.
The way Williams' defense is set up, he relies on 4-man pressure to allow his back 7 to play zone coverage and clog the throwing lanes while giving his corners the latitude to play the QB and the ball. Those cushions you see are designed, in some cases, to account for dropping linemen after showing blitz during pre-snap. Takes away slants. Sometimes that works, and sometimes it doesn't. If coordinators could predict (cough, NE, cough) what an offense is going to do with 100% accuracy, there would be pure dominance out of any defensive unit. As of now, our pass defense really isn't a huge issue. Now when the run defense sputters, that's gonna effect everything. ESPECIALLY pass defense. Because now you have to commit to stopping one thing which produces vulnerabilities in the other.
I'm rambling, but I had a stream of thought and wanted to let it play out in my head. lol.