There will have been a myriad of different things going on behind the scenes at City of the past few seasons, all of which have culminated in the decision to sack Roberto Mancini. No-one on here will be privvy to the full picture, some will have no clue whatsoever and are basing opinion on gut instinct and media spin whereas others will have snippets of information from various sources but far from a definitive viewpoint.
What seems pretty inevitable from the volume of stories and rumours coming out of City over the past couple of months is that Mancini's position had become unteneable. A growing number of players had seen their relationships with him deteriorate to the point where they felt they could no longer continue to work under him. Add to that a breakdown in relationship with some of his backroom staff, and then probably even more importantly those above him in the hierarchy and it almost made the on pitch results irrelevant with regards to his continuation in the role. The fact that, coupled with the off field issues, the on field performances and results were less than expected as well, Mancini was never going to be able to ride out the storm.
Mancini's management technique is one which, it seems, brings results very quickly, and this was exactly what City were after 3.5 years ago. We hadn't "arrived" as yet as a legitimate top side, we'd never qualified for the Champion's League, and were still trophyless. Mancini brought us all of those things, and in pretty quick time. However a side effect of this was that Mancini's techniques and methods, whilst bringing instance success, also brought with them issues and baggage. His approach was 100% stick and 0% carrott. Short term that's ok, people can deal with it, long term it starts to wear on people and eventually more and more become disillusioned and resentful of the way Mancini behaves.
City have reached the stage now they have "arrived", it's now a case of achieving longevity. We need to still be at the top in 5, 10, 15 years time. That, alongside the restrictions FFP brings, means we need to approach the next few years, and the future in general, in a different manner to the last few years. We simply can't be spending tens of millions of pounds each an every season on established stars, we need to create our own stars via the expensive academy complex we're constructing. This brings with it a new set of aims, and a top-to-bottom approach, or a "holistic" one to use City's vernacular. Some managers can easily accomodate and fit in to this type of approach, others can't. Mancini is not one who this comes easy to, and is unlikely to be willing to change his ways, Mourinho is another who isn't likely to find such an approach a natural fit. This is just another reason why Mancini's days were numbered.
Ultimately I don't believe the on field results would have been enough to see Mancini sacked, had the off field situation been a more healthy one. If Mancini was buying into the ethos and plans, and was man managing his own relationships with the various groups behind the scenes in a better manner, I feel he'd have remained as the manager. He'd likely have been given a "it's got to improve next season" kick in the arse from either the Barcelona duo, or Khaldoun but ultimately he'd have still been City's manager.
Mancini is a winner, but he's JUST a winner. When he isn't winning, like this past season, he isn't bringing enough to the table to make up for that fact.