I recall reading he felt himself most comfortable in a number 10/central. That's where he come through the academy. [Edit.
Found it]
A lot have been wanting Everton to go to a 3 man midfield when we've never really had 3 decent centre midfielders fit. There was some opinion that Gordon could go in the middle, if we did we need a winger to replace him out wide.
So perhaps if we can't afford/our preferred centre midfielder isn't available, then El Ghazi wide and Gordon in the middle could be one option.