This thread has got very heated and it's time to cool down and think clearly.
If a better manager than Mancini becomes available, then that manager will be recruited in the same way that better players [in theory] will be recruited in a bid to take the club forward. And that's the problem. IN THEORY.
I can remember the situation in the early 1970s when City were one of the game's dominant forces under the management duo of Joe and 'Big' Mal. Joe, the older guy with the cool head, and his colourful and eccentric sidekick Mal who probably had more input than most other club's number two's. It was a winning combination but Mal wanted more control and the new boardroom recruit, Peter Swales [ironically taken on board as a 'peacemaker'] found a way of getting rid of Joe, with Mal acquiring full control. That was a decision that split the fans, but with the benefit of hindsight, it was the beginning of the end and the club went on it's downward spiral. It was a slow movement at first and we still managed three Wembley appearances within a decade of this move, but the decline accelerated after that.
The way City went after Joe's removal was one of constant management upheaval, and when I read some of the posts on this thread, I can only assume they come from people who were neither born or were too young to have been following City in those troubled days.
The last thing City need to do is to ditch a manager with a successful record in the hope that we can, somehow, find perfection in someone else. We won't find perfection because perfection in this game does not exist.