DaWolf brings up a good point. Teams don't always hire the GM first, particularly if a high caliber guy comes in as HC who wants his own people there.
That being said, I still like the GM, then coach, system of doing things. And if we were to go that route, I would prefer Marc Ross to be the guy.
He might go the Perry Fewell route (and there could be worse directions, IMO), but he also seems less bound to a "way" and more freethinking, based on what the Giants have done in the front office and on the field.
He's young, intelligent, has a track record in scouting/drafting, and is well-spoken of by those who know him. I would be excited by a Ross hire. If another team doesn't get to him first, that is.