Originally, the intention was to create positions to serve as sort of internships for up and coming coaches early in their careers, not for fired head coaches living off their old contracts. And naturally, the big monied schools found another way to give them even more advantages.
Basically these folks are assistants to the coaches and they cannot coach players during practice or games. Alabama seems to have cornered the market on hiring higher profile guys while they are collecting checks from their former employers. I think these guys learning more from what Saban /Alabama does than the other way around.