IMO, with the right delegation of responsibilities, the HC shouldn't matter. We have a great GM and personnel guy, IMO. Let Andy and Omar choose the right OL coach and maybe we can get Munchak or "poach" Jeff Stoutland from Philly (maybe they have some sway. Let the OL coach teach and evaluate our players strengths and design a run game and passing protection plan around it. Then, hire a Run Game Coordinator and a passing game coordinator to study what successful teams do and replicate it within our structure. Then hire Hines Ward to coach up the "head cases" we have at the WR position to turn them into animals whether they are blocking or trying to get open. They will learn to take pride in their craft. Do the same with a TE coach like Heath, who can teach them the same things at the TE position.
NOW, we can hire away a Bobby Slowik as an OC/Assistant HC. Offense done.
Hire a defensive minded coach with "pedigree" (to use a Tomlinism). Maybe we could get Flores, Bob Stoops or even Butler to come back, but if not, we go young and get a guy who has a history of overachieving. Let him choose his staff so they will be loyal to him and not the HC.
Now we can hire a HC that is just a guy that doesn't "meddle" in everyone else's job. Just a manager with a talent (and an edict from his boss) to let his coaches do their job.
He gets all the credit and is therefore replaceable.
Switzer, like Tomlin, took someone else's team to the big game a few times before he actually thought it was his team. Tomlin's ride is over, trade him or take away his power to meddle and we could be just fine.