If Grealish and Harry Kane are both transferred to Manchester City, Manchester City will have sufficiently strengthened their squad. They managed to keep the squad from last year mainly.
They will seem to have paid a very high transfer fee for these two transfers (about £230M) and I think they will give a lot in return with the trophies they will win.
Their squad already are dominant strong in the Premier League. They only pay more attention and resources to Champions League, and sometimes they got troubles in Premier League.
Kane and Grealish, if they come to Etihad, will make Manchester City becomes more dominant in Premier League. They will bring more choices to Pep Guardiola and they can bring that power to Champions League and help Manchester City win the first title in CL.
Man City does need a striker, at least to replace the position left by Aguero. Harry Kane is indeed a good striker, and he is shining right now. But are Man City willing to spend £160 Million just for a Harry Kane?
With £160 Million, Man City should be able to get a striker and 1 or 2 more players. But if Man City are really attracted to Harry Kane then the transfer with fantastic value will really happen.
Kane is not only a good striker but also among one of the best strikers globally now. He can score a lot of goals and I believe he can score as many goals as Lewandowski if he gets good supports for outstanding play maker like De Bruyne.
In the last season, Kane shows us his another skill, assists. I did not know Kane can play well and can make many key passes like that. Mourinho discovers that skills of Kane and gave him a position in Spurs to show it on field. With this, Kane contributes more to the team and his contributions are not restricted to goals he scores.