I agree with you on your points above, because Mourinho is a coach can cannot do without wey itu players and he knows the kind of players that he needs to become successful at the end of the season. When he did not ha ve those players he will not be able to perform well in that season. Assuming Manchester united gave him the players he needed, he would have done something great during his time in United.
It was the same thing Mourinho said in Roma that led to his sack because he asked for players but look at it now Roma is suffering from a big problem because their performance is declining since the last quarter of last season. Wrong decisions by a club management can make the club suffer for long.
Jose Mourinho knows how to win trophies. He doesn't need the club owners telling him how to do his job. The Glazers did not give Jose Mourinho the freedom to pick the players he wanted in the transfer market like other teams he managed in the past. I saw in one of his interviews where he was asked about signing Didier Drogba at Chelsea in 2004. Jose Mourinho told Roman Abramovich to pay and not speak. We all know how successful Drogba went on to become in the premier league and for Chelsea. This was Mourinho’s style and he must have rubbed club owners the wrong way. Clubs do not like a manager they cannot control and will look for any excuse to sack you.
But it is important for managers to establish a good relationship with the club owners. If the club owners think differently or have doubts in some certain things, if the manager has a wider range of knowledge in those issues, I think it is wise for the manager to explain to the owners and make them understand why they should do things his way. No CEO would want to keep or aid a manager that's they think is not loyal to them. We only heard Mourinho side of the story, there must have been a reason why the Glazzers didn't backed him fully the way he Mourinho would have wanted. Let's not forget that Mourinho have some level of pride in him.
Good relationship between the manager of a club and the owners helps the team to be together, a divided house can not flourish, when the manager is not in a good terms with the management the whole situation may affect the performance of the club entirely because the manager may not be concentrating in his coaching jobs and players also may not have the zeal to give their best in the football pitch I so doing politicsay be introduced in a way that individual players decide whom to support in the ugly situation either the club owner or the coach and this may lead to underperformance of the football club.
No matter how good you are as a manager in as much as you were hired by a person or group of persons, you are answerable to them because there are conditions that made them to hire you as such you don't act on your own, although many managers has used their coaching strategy to bring success to a club and thats the purpose for their employment but before you make any step as a manager, you must involve the owners of the club before anything although sometimes club owners are very annoying in terms of decision making.
As for morinho we know that he is not a bad manager but he is arrogant although am not judging him because different people has their personal character but I believe that what happened may be as a result of his attitude and nothing else.