It seems to me teams have picked up on what Denver did and are using hybrid Denver defenses to stop Dallas. First, they are playing a lot of man-to-man coverage on the Cowboys WRs, none of whom are fast enough to just run away from CBs. This is why we are not seeing a lot of separation. Some defenses have played press as well but you need the personnel for that. The other key piece of this has been the pressure on Dak. Some teams, like KC, were getting good pressure from just the front 4. Some were sending extra guys. When I rewatched the Saints game I saw more blitzing than I did watching it live. I think the goal is to play tight coverage and force Dak to make quick decisions. If the Cowboys were a decent screen team they might have a lot of success with that play. But it seems every time they run it the other teams recognize it almost immediately. In fact, has anyone else noticed how passes to the flat are almost always stopped dead by other teams while against Dallas those plays often go for 10 yards or more? One thing Dak could do to change the defenses a little is to run. But he is slow to make that decision and when he does he is getting caught from behind by defensive linemen. It seems almost every game a DT is catching Dak as he tries to scramble away from pressure. He does not have the speed of Taysom Hill or Jalen Hurts.