Grealish is the almost perfect control player in the City system. With Foden et al in the middle, much of our ball retention, tempo control and game management is done by Grealish and Silva on the wings. Eze is your typical English wideman/playmaker who dives towards the goal or an attacking movement at almost every opportunity. He's essentially Foden 3-4 years ago or Doku now which is fine unless you're 26 and coming off the best season in your career.
There's a reason Doku doesn't generally start games when Grealish is in form and comes off the bench, and it's the same reason why Eze wouldn't get a look in either. In bigger games we can't use him, and in smaller games we don't need him. He doesn't have the brain and we already have two young lads with similar skillsets that we're trying to improve that aspect of in the same position. Any more would feel like a job lot.