My opinion is still too swayed by Mou's past - he's left most clubs after 3-4 seasons after falling out with people
This isn't an argument to make you reconsider your stance, or maybe change you mind mate, because everyone is entitled to their opinion - and that's fair enough.
But wrt the part quoted above, he fell out with the players/ upper management at Real Madrid and Chelsea - clubs that have a history of players running the show in collusion with the presidents who have their own favorites, and keeping managers on a short leash - with a list of insta-sacked managers that includes Champions League winners Juup Heyneckes and Carlo Ancelotti; La Liga winner Fabio Capello, two times Champions League/ La Liga winner Vicente del Bosque, and Manuel Pellegrini. Since the ousting of Del Bosque in 2003 (for reaching the semi-finals of the Champions League, and winning La Liga - how very dare he!) - Real Madrid have appointed 12 managers in 12 seasons - and José lasted the longest. At Chelsea, they appointed 7 different managers in 6 years between Mourinho I and Mourinho II. So we must consider the modus operandi of the cubs he's managed. At Porto, he had to leave because the players were going to get poached, and they were not at the elite level of European football. At Internazionale, the call of Real Madrid was too enticing to resist (no one can resist Madrid because of their history and accomplishments, plus he would have the chance to overtake Pep in the league - which he did in his second season).
Also, José is a very complex character - but people only see the bad in him, and it's imperative that we understand what makes him act in certain ways. This is someone who was told he didn't have the physique to be a footballer like his father Félix Mourinho. He was a scout, a youth team coach, a coach in god knows what division of Portugal with Estrela da Amadora, a translator, a training coach, an assistant. He worked his way from the very bottom - step by step, after being considered a failure as a footballer, and people like that always have a tendency to be snappy when they taste success because they always think they have something to prove to the naysayers. This is why he is so bitter towards Barcelona (who still consider him to be a mere interpreter for Bobby Robson). This is why he's petulant and arrogant - something that was fueled even more because of his meteoric success.
However, for the first time in his career, Mourinho has faced major failure as a manager - first at Real Madrid and now at Chelsea. There's a train of thought that says he's a broken man, or he's taken a step back and will never be the same; but I honestly believe all these events (and the poor health of Félix Mourinho because of brain surgery) will make him reconsider his stance as a manager, and maybe humble him a bit. Then you talk about United, and we indulge our manager - give him the sort of power he wouldn't have at Madrid or Chelsea under Florentino and Roman - something that was the root of superficial issues at both clubs. Plus, even back in 2004, Mourinho said he wanted to manage United and Liverpool at England. When was the last time he said something disrespectful towards United? Never, right? His biographer said he was distraught after David was appointed as Fergie's replacement. This is the job he's wanted, and the timing couldn't be better - a disgraced manager joining forces with a club that has lost its hallow, so to speak.
Also, wrt the pragmaticism part too - in all his seasons as a full time manager, José has never finished outside of the league's top 2 in terms of scoring apart from the 2013/ 2014 season at Chelsea - where they finished 3rd. That's a hell of a record for someone who's been stereotyped as a defensive coach primarily because of his big game tactics where being cautious can be the difference between winning and losing - because margins are wafer thin. Even Fergie's United played some dreary football for the first half decade of his tenure, our first League winning team under him was extremely functional; and again in Europe after THAT defeat to Real Madrid. So it's not like United has always played champagne football, even under Fergie. If we get Mourinho the attacking pieces he needs, he can build a beautiful counter-attack like he did with Madrid (who averaged 108 league goals per year under him, and set a new record for goals in a Liga season).
His career overall is a bit misunderstood IMO, and he's just a very easy character to hate (in the genuine sense of the term - not pop lingo) because of his pompous nature - which can color objective arguments (not saying you weren't objective in the assessment mind, far from it - and again it's just a matter of opinion, which is perfectly fine).