I genuinely have no idea, is Callahan the one who ranks the kids? Or is he more of a journalist and they have guys behind the scenes with legitimate experience who evaluate the kids. There has to be tons of former college players, coaches, etc. that want a gig like that, but without being a journalist.
Callahan and the HOL crew get input on the rankings - who needs looked at again, etc. - but they don't actually do the rankings themselves.