Well if Mancini hates it so much he can threaten to quit and go to Juve again...because as has been made abundantly clear...he doesn't have the 100% control he wants.
What you've posted above is wild speculation as you have no way of knowing how the Sanchez deal unfolded, nor do you have any way of knowing which player is who's target. You've done your best in this thread to paint Cook and Marwood as incompetent whilst holding Mancini up as a hard done by manager struggling to get the players he requires. I just don't see the situation like that at all.
Of course it's wild speculation. I don't think Cook and Marwood are incompetent, but there are things about the situation that bother me.
The club appears to be run by committee. We're intransigent, inflexible, slow to react, still overpaying and too keen on established names.
If the blame for all that lies with Khaldoon then so be it, the guy scrubs up well and gives a fantastic interview, but he's in charge of the whole shebang, and mistakes have been made. My gut feeling however is things a little further down the chain might not be ideal. Cook is clever, and has done well to modernise the image of the club, but the suspicion, that his vision of the club interferes with the optimal management at squad and team level, has never gone away.
I couldn't give a damn about Mancini, really. Sink or swim time for him. But what bothers me is that, if we fail, then the tendency is to blame it all upon that one guy. If that happens, I'll be distraught, not for the thought of poor Mancini the multimillionaire serial medal collector bit of a bastard handsome devil... but because the larger problems will remain. I can see the track record of others is pretty lacklustre, I can see why Mancini would draw attention to this.