Mate , apart from probably Branthwaite, every Everton player is on more than they are worthKeane was a regular starter for us for a good while, I don't Holgate has ever tied down a regular starting place, certainly not in the same position (I know he has covered a few areas when injuries have hit).
By that it makes sense Keane should be on a 'better' contract than Holgate, but certainly not to the extent that he is on.
Them 2 and Godfrey are on far more than they're worth.