Imo, Pep's system works perfectly only under two conditions:
1. When you have Messi
2. When you have 10 playmakers on a field who interchange positions, with a true No9
At City, he is in problems.
Without Messi, he'll never win a CL.
And it often seems that he lacks a killer finisher since majority of his players are attacking midfielders.
On the other hand, now with Haaland, he'll get some goals and individual stats.
But imo, City will lose tons of "that what made them City".
They'll be less fluid, less unpredictable, more static.
No matter what he does, Pep probably won't win it without young Messi.