John Hughes was a terrible player in 2012 before Horton changed his path. Hughes was a rotational defensive tackle that was often stone walled as a pass rusher and really didn't look strong against the run. However, in 2013 Horton came in and made him a 5-technique and he turned him into one of the best space eaters on the team.
While it may not be a great comparison, I see a lot of similarities between his situation in 2012 and Sammie Lee Hill's situation in 2013.
At 6'2" 320lb. Hughes was an inch shorter than Hill, but both carry their weight similarly. Both have a wide frame and fit the role of space eater and pocket pusher, more than player like Karl Klug and Jurrell Casey that can slip blocks and penetrate in the backfield.
Both of these players have been and are likely to always be rotational tackles.Their roles are more to cover up the edge rushers and set the edge so that the linebackers can have a clear path at the ball carrier or the quarterback. As a non-starting player he will be able to spell the starters or play as a role player on run downs. I imagine he will play around 500 snaps per year (32 per game) to insure the starters stay productive.
Both posses the ability to lock down blockers and work down the line to prevent lineman from moving up to the second level. They also both posses the ability to beat one-on-ones if they are asked too, though that isn't their primary function.
If Ray Horton can take Hill and develop him like he developed Hughes, then Hill could solidify his spot on the roster as a two-down 5-tech behind Ropati Pitoitua and possibly Derrick Morgan (or whoever the other starting 5-tech is).