Grealish
Ruben Dias - he was superb when he first came. Remember why Pep signed him? they were having a bit of a shit start and losing at (home?) to Leicester by some shit high score. Pep found a solution though, spend £50m on Dias and he did solve that problem. For me , he seems to have gone backwards for the last 2 seasons.
Laporte - again quite underwhelming since he joined City
Cancelo - great at first, prob fell out with Pep hence the swift departure?
Doku - even he is less exciting (ok he only just came back from injury time will tell)
Leory Sane - he was again exciting to be begin with, complete fell off towards the end of his City career
Kalvin Phillips - i dont need to explain
Probably have missed a few, but if i look at the positives, i would say, Stone, Walker are the two main one that I think has improved under him. I try not to include KDB, Silva and Rodri as they have just kept up with standard, not improved.