It's called Mangum beating Hosick out for the starting job after a full year in the system. It's not in someone's best interest to have them sit around and rot. If he's better, he's playing. And many indications point to him being great as long as he doesn't end up a mentally soft guy in games like Heaps. And there's no indication he's weak.
No way Hosick starts for 3 years unless he's absolutely amazing. You seem to think that you just don't play a guy period because of his year. Why? Freshmen all around the country are stepping up having great seasons. And I'm talking pretty dang good, not Heaps "record breaking" good. lol
And he won't be a true freshman in 2016.