Does it matter if none of those years were spent calling plays? There's nothing out there that simulates calling a game, therefore you need game experience to become accustomed to it and to hone in on what works and what doesn't in different situations. Like anything, becoming better at your craft takes time and experience.
As far as the scheme being the issue - people need to realize this is the same scheme Atlanta had last year that set scoring records. The scheme is not the issue.