First, let me say that both programs seem to have great training regimes and hardworking kids who are also talented. I think both programs deserve celebration because they really seem to build kids up rather than tear them down.
However, as a (former) coach and current teacher myself, one thing leaps out to me after having read the Letsrun profile on the Hunters. Bill Aris at F-M does not have a job other than coaching. Neither does Joan Hunter… though being a stay-at-home parent definitely has some demands. In most programs, you have the combined teacher-coach model where classroom teachers or PE coaches also coach the sports team.
HS coaching has clearly taken a leap. I think 10-20 years ago, it was enough to have a "pretty good" workout schedule with some individualization… say maybe an A, B, and C group for workouts based on past mileage and experience. Now, it seems the top programs are writing workouts for individuals, much like an NCAA model.
Individualization takes time. It would seem, on the surface, that having a coach without outside employment (and therefore, a full work week's worth of time to devote) is a big advantage. I would imagine there are also highly devoted teacher-coaches out there who stay up late into the night doing the same thing themselves.
I am NOT assigning all the success of F-M and LV to this. But, I would be interested to see if others think it may be a factor.