Personally, if Garrett is retained, I’d fire Linehan and put Garrett back in charge of the offense. The last time he was the OC calling plays, we had the #2 rated offense in the NFL, and that was before finally rebuilding the OL. He’s been around long enough to do both...prove himself or be replaced soon after. If you’re going to fire a guy, at least give him a chance to do the thing he was good enough at that got him two head coaching offers before you promoted him.
I’d also fire Marinelli and bring in Ray Norton Jr or hire George Edwards away from the Vikings.
Then the front office needs to be active in FA if a player in a key position is available, along with having an effective draft that balances the front 7 on defense with skill players with big play ability on offense.