I think he is a player you must keep. IMO you can have specialist players in your starting XI, but it's more useful in your subs to have some versatility. Can can play CM, CDM, CB, and RB. He is technical & strong. He has his limitations, but he is about as good as you can get for a bench player that can play multiple positions.
Matuidi & Khedira are much more limited. Although Khedira I think will work in the system. He is a system player. Coaches love him for that reason. He is very good at doing what coaches ask of him.