I disagree with your line of thinking in a couple of ways. For one, you say it changes things if Foster commits. We have 9 years of evidence on Fran's recruiting. One player doesn't change anything on how good Fran recruits. For two, you say they might out perform their rankings. If that happens, does that mean out of nowhere Fran was a good recruiter after all? Or did he develop them well? Or maybe he just got lucky with them.
In my opinion, after this long in the program, Fran has pretty much proven what he is as a coach and recruiter, regardless of one recruit or one class. It's possible he can string together a few good years and get the ball rolling to move up a notch, and it's possible he will get a little lazy with recruiting like Davis did and move down a notch, but as of right now, he's a consistent "one or two games from the bubble either direction, every year.