I guess you haven't watched much of Cowboy's football the last few weeks. Since those guys have been out Parsons has been on a tear coming off the edge, however, opportunities will be lost for Parsons when Gregory comes back. Now I'm not say that won't be good but I don't see Parsons getting the same number of reps at the LOS that's all.
Consider this. When Gregory went down, he was reaching his zenith and creating havoc for the offense.
DLaw played well. I am not a fan of his, but with Gregory he can cause confusion and get the QB off his spot.
Now the offense has to respect Parsons even more, because he is not lined up in a conventional rush the passer position.
Will he be blitzing on this play or not?
And sliding Tank to a tackle spot, since he is good at the run game, and both he and Parsons line up next to each other, what happens on Gregory's side? Who is there to chip Gregory with an RB when the stunt games Parsons and DLaw are playing is overwhelming the offensive line.
Who are the three linebackers when Parsons rushes? Will they not still be there?
Quinn will be opening Christmas presents with this defense and what he can do with Parsons.
If the offense has trouble with Micah when they know where he is and what to expect. What happens when he is moving around and picking his gap?
You are overthinking this.