I think some people are not aware of just how much our pass rush affects the opponents game plan. They have developed plays specifically to take Parsons out of the play. There are some plays I see him take on a double-team on the line and then get chipped by a back. Several teams designed plays to take advantage of his ultra-aggressive pass rush. They run the delayed draw to his side knowing he will be up the field in seconds and their runner can sneak inside. They throw the slant or similar routes to his side knowing he vacates the end so quickly the receiver will be open.
As others have said, the key to beating Dallas's defense is gaming the pass rush by getting the ball out quickly, negating the pressure. Screens, quick slants, out routes, etc. Three step drop and the ball better be out. Very similar to our first game when MM schemed a bunch of quick passes where one receiver clears and the other runs an out behind him, or when the back fakes the run and runs to the flat or to the center of the field for a dump off. The QB always has an open target when he hits step three of his drop back. It isn't pretty, but if they can get 3-4 yards a play they're in business.
Parson's will get his sacks. But look at it this way, I would rather totally disrupt the opposing teams game plan than have an additional 2 sacks a game. And when we disrupt the game plan and get the sacks, sweet!
BTW - I think the SF game wasn't what everyone thought it was. Rather than a more talented team beating up on the Cowboys, I saw it more as SF game-planned the hell out of that game to beat us, to the point I think they probably worked on us even during previous weeks. They were busy getting their butts handed to them the last several weeks by less talented teams. I think we get another shot at them the outcome will be different.