I realise I'm in a small minority but for me he's still not shown he has the skills to succeed in England with a club like City. His fans might say well of course he hasn't because he's never had to do that but that makes it a big gamble back in 2013 to base the whole future of your club on a skillset he may or may not have.
What he did at Barca was to mould the 2nd biggest club in the world, with all the advantages that entails, around a genius - we don't have a genius to build around and we're not even the 2nd biggest club in England.
Bayern are uber dominant and each summer poach their rivals' best players so winning the league there doesn't mark him out as outstanding. Both full CL campaigns he's overseen there have ended in comprehensive humblings by top teams. So what's he added ? Pretty football. Most passes in a game ever. Most possession ever. Not when it counted in Europe though.
Tiki taka doesn't work in England namely Arsenal. Why should it work at City with slightly better players ?