If you really believe this, here's a question for you. How does Boise State attract coaches who are so much better than anyone else's coaches at teaching the game? Boise State has done it for a long time under a lot of different coaches. Why are they always able to attract better coaches than 99 percent of the teams who also recruit nothing but 2 and 3 star kids?
I think it has more to do with evaluating than coaching. They can attract overlooked 2-3 star kids and they compete against teams that are not getting high-end recruits either. They build a winning atmosphere with these kids in a weak conference, build up their confidence and think they can take on anyone.
That attitude is a big part of why they are able to compete occasionally with the big boys of college football. If you have confidence and a winning attitude, you can sometimes overcome a lack of talent against those teams that should be better on paper.
I know one thing for sure. It's much more complicated than just better coaching. Everyone has professional coaches on staff. Some are better and some are worse, but I would think the difference is not that great, otherwise they'd be brick masons instead of coaches.
It's also the level of competition. Put Boise St. in the Big 12 or the SEC, and see how many 0, 1, or 2 loss seasons they have.