What interests me with the man city link is what would their expectation be of his game time with them.
Grealish has probably played an average of 35 games per year for the last 5 years. We'd expect next season fingers crossed to be his highest with Villa, ideally with a cup run and england appearances, so maybe 40 with a few games out.
But Mahrez, Foden, De Bruyne etc play 55 games every season. It's a hell of an ask to play 20 more games per year than you're used to.