re: Had Nick Saban stayed at Michigan St. would he have won a National Championship there?

No.
3 different coaches have won a title at LSU recently. Its just at a different level of potential than MSU. Bama the same deal.

Hard for B1G teams to win it all. They have to build a little different. They have to have the brutes to handle the cold and beat a team like Iowa on the road in November. And they need the speed and skill to compete at the highest level in bowl games and good weather games.
No recruiting advantage in the North either with the weather and the lack of black athletes not interested in basketball.

Ron Dayne rolled thru Nick Sabans Spartan D when they met at Camp Randall during that 10-2 year.

I think Dantonio did a hell of a job there.