Not positive about this, but I think those levels of prospect, pro, rookie, all star, hall of fame coaches, is based more on time playing the game and seasons played then anything else. And if that's the case, it should have no impact on prestige of a school, because the coach might not actually be good.
And even if it is based on success, still don't think the idea makes sense, because no coach should be given credit based on success he had in a different world. Everyone has to build their teams up, that's the point of the game.
Just my thoughts.