How awesome was Mike McCarthy's resume before he was hired? How great did Sean Payton look on paper? How are McCoy, Roman, Carmichael, or Bradley any worse than them?
No one knew that McCarthy or Payton looked great on paper before they were hired, that is a risk those respective franchises had to take. It's also a risk that will never pan out for our franchise because those coaches are given latitude in their respective cities that Jerry Jones would suffocate out of them as rookie head coaches here in Dallas.
I'd love a McCarthy or Payton now that they are established and can command respect and call their own shots to an extent (and even then, they would come here and be neutered to an extent and they'd be less effective here than they are in GB or NO).
The rookie coaches who could come in here and do things the right way with Jerry breathing down their necks are few and far between.
I'm not saying those unknown guys don't exist, I'm saying they have no shot here at developing into great coaches. You either need a surefire guy like Harbaugh who comes ready-made demanding respect, or you need a guy who is accomplished enough to demand respect but not so washed up that they are just grateful for the opportunity to get a last paycheck.