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.
Yes it is good for managers to have a good relationship with the club owners and sports directors. It certainly helps increase the longevity of the manager at the club. But if the relationship is dependent upon the manager compromising or going against his own guts and vision for his team then the boat is headed for rocky waters. Club owners should give managers the freedom to do their job. The problem usually comes from club owners asking managers to sign big players who may not necessarily be a good fit for the team. I cannot dispute the argument that Mourinho is proud, but I disagree with those that say he was toxic to the club and the players. What did Mourinho’s successors at Manchester United have that he didn’t? Yet Mourinho did not get the same leniency given to Ole and ETH.