Let me start by saying that Pep Guardiola is an exceptional coach, quite probably the best coach available to any club at this time. But, let's play devils advocate for a moment.
Guardiola inherited a Barcelona side on the verge of something special - with one component well on the way to becoming extra special.
His haul of two C Lge & three League titles, in his four years in charge, were a fantastic achievement. There were various other cup successes as well. But, let's be realistic - it's only League titles & C Lge wins that are important for the super clubs.
After a year with the sadly departed Tito Vilanovo in charge, Luis Enrique took over at the Camp Nou. Is Enrique spoken about in the same glowing terms as Guardiola yet? No. Why not?
His record, to date, is one C Lge win & one La Liga success - both in his first season. There has also been various cup wins as well.
Barcelona are still in the C Lge and ahead of the Madrid duo in La Liga. Come May, Enrique will almost certainly boast another La Liga trophy, and quite possibly another C Lge
If he only won the League, it would mean a C Lge win in two years (50%, success, which would equal Guardiola's strike rate) and two Lge titles in 2 years (100% against Guardiola's 75%).
And so - to Bayern, where Guardiola has won two Bundesliga titles in his two seasons. He and Bayern are odds on to win another. He hasn't delivered the C Lge though. I've said before that there's a case for arguing that he's failed in Germany if this is the benchmark.
His predecessor, Juup Heynckes, won both the C Lge and the Bundesliga in his final season (and the German Cup) before Guardiola inherited that team.
It's also worth nothing that Heynckes' main rivals in his three years in Munich were a powerful Borussia Dortmund, who Bayern raided for two of their best players - Gotze & Lewandowski.
Now it can't be cut both ways, Enrique can't be the coach who inherited Guardiola's Barca, yet Guardiola not be the coach that inherited Heynckes' Bayern. A much more simple explanation would be that it's players that win trophies.
So, let's have a look at Manchester City. Roberto Mancini's one title in three years is matched by Manuel Pellegrini - although Pellegrini could yet win his second this year. Pellegrini inherited the side that Mancini built with the likes of Hart, Yaya Toure, Silva and Aguero in it. He gave Hart his chance and signed the others.
That quartet are largely responsible for putting the blue half of Manchester at the forefront of English football. What did Pellegrini add of similar significance?
Guardiola is now the man in charge of buying and selling - an area that's going to be fascinating going forward. When he took over at Barca he told Ferran Sorriano & Txiki Beguiristan to get rid of Deco, Ronaldhino & Eto'o.
Since joining Barca and starting his coaching career at the very top, Guardiola's stock has risen immeasurably. So a man with the 'balls' to insist a teams' biggest stars are discarded before he accepts a role most would have jumped at, is very likely to have even more belief in himself now. What instructions have been passed to the City hierarchy this time? History would suggest that Yaya has been a topic of discussion!
City are primed to be P Lge winners for many seasons to come, but are they in a position yet to win the C Lge?
Barcelona's success in Europe was because of the players they already had. Bayern's the same.
City need at least six before they can compete with Europe's best - but where are those players?
The best are already at the best clubs, winning trophies and competing at the highest level. They earn salaries that mean they can make life choices rather than financial decisions.
Raiding Juventus for Pogba is an option, but that's also an option for Real and Barca. Perhaps Guardiola can go back for Lewandowski? Both will command huge fees. Raising that money from players Guardiola doesn't want is unlikely to be enough.
Guardiola will be successful at City. League titles will follow and they'll regularly get out of the C Lge group stages. But, to get to the next level, with real European success, is a much bigger step than some imagine.
Pellegrini and Mancini were both capable of the above. They're very different personalities. That was underlined by Pellegrini's dignified announcement that he was leaving. Would Mancini have reacted the same way? I suspect not!
City's talks with Guardiola started in 2012 - they've admitted that themselves.
What chance that Sorriano & Beguiristan looked into the future, and thought that a smooth transition from the well respected Pellegrini to Guardiola was a better option than the exorcism of Mancini would have been after 6 years of success? And six years of success it would've been. Me too.