The average tenure of a GM is 4 years, excluding the GMs in Dallas and Cincinnati, where they are also owners. On the surface, a GM who inherits a great roster is going to look better than one who inherits crap. Usually, the first thing a GM who inherits crap does is hire a new coach. Then he begins remaking the roster.
If you look at the Panthers in the four years before Hurney got here, they averaged 5.3 wins a season. If you look at his first four years, they averaged 9.0 wins a season. That's not counting the playoffs, BTW. So as far as hiring the right guy and remaking the roster, Hurney doesn't suck.
In his next four seasons, he averaged 8.75 wins. And in the last two years, he's averaged 4. What should be noted here is that the 2 win season had a lot to do with JR's direct instructions to cut vets and let Fox work out his contract.
I would say that in his first eight years Hurney did a pretty good job of building a competitive team, without the benefit of a franchise quarterback. Now he has Cam Newton, and that alone should make his decisions look a lot smarter. Does it suddenly make him a better GM?
And for what it's worth, among active GMs only A.J. Smith had a better turn-around after taking over the football team.
That metric may mean something to some people here, it may not. But it's still a fact, so have fun turning it into an argument for the pre-conceived notions you already have.