Pep so far managed 3 clubs where he had everything going his way.
In Barcelona he has merit to make that team up but when you get Messi and the Spain golden generation core appearing in your time there's also a part of luck there, even if you also worked for it.
He then proceeded to screw up by getting rid of Etoo and getting Ibrahimovic (from Mou's Inter) which didn't work out for his system and in the following years watching Real build up and threaten his hegemony, which Real did, and in that precise moment Real was good enough to challenge him directly he left. I don't blame him, he had won everything with Barcelona, but in this analysis that timing clearly cut out a period where he could have been faced with competition from a team that matched his own.
In Bayern and City he had immense advantages.
In Bayern he inherited a treble winning team that had reached 3 CL finals in the 4 years before.
Reaching a CL final is not a sure measure of quality but he way he failed it says something - every time he faced an equal opponent he was crushed (0-4 at home to Real and 3-0 away to Barça) and with decent but not as good teams he struggled (losing to Atlético and struggling through extra time to get past Juventus). The only knock-out games he dispatched easily were against opponents one order of magnitude below his team.
In City he inherited an already very expensive team that was champion 2 years before, with a core of great players.
He then proceeded to just spend what others couldn't, amassing players after players and getting rid of the ones that didn't work out with no problem.
His team in City has been most of this time basically 2 teams, most of the players in his bench would start for any other team in the league.
With this squad he can rotate half the team and rest players with no drop in quality which left him with no consideration needed on what game is more important or not.
He did a great job in England and of the big teams the only one that was good enough to challenge him were Conte's (Conte won the league in the first year) that followed by lowering in quality quickly and Liverpool which rose in quality with Klopp.
He was fighting no one else: Man Utd was horrendous, Spurs are Spurs, Arsenal was still a wet noodle.
So he basically had to compete only with Liverpool after the 1st year, a Liverpool that again didn't have the luxury of his wide and star clad squad.
Then comes the CL and he failed miserably year after year being humilated by teams much weaker than his', he needed 6 years to finally beat it and when he did he benefited from other great teams either aging or not being able to afford the financial investment to keep / improve the squad especially after covid (not a problem in oilland).
Last year which big european team was good? Real had serious weaknesses, Barça was bad, Bayern was bad, he basically had no opposition, and that is where Pep shines: when he has a team one order of magnitude better than everybody else.
After Real Madrid on the other hand where did Mourinho get a team to challenge for the CL and the national titles seriously?
He did in Chelsea and he delivered, in his first year there he got 3rd place with a team with holes (winning home and away to the 2 teams above his') and the following year he bought 2-3 players and got the title.
He failed in his 3rd year spectualarly (fired when being almost in relegation zone) and then he had no other serious job to really contend in the level Pep had.
Man Utd were nowhere near a title challenge with a rotten useless squad, he actually won some minor things, he probably could have left Utd in a better situation but we're comparing to Pep and it's not possible, each one had very different tools to work with.
Then he went to Spurs.
Then he went to Roma, the perennial loser in Italy that was finishing in the lower CL places / Europa League places in the years before. He won a minor title there (something rare in Roma) and again maybe he could have improved Roma more by now but in the comparison Pep is sleeping in a completely different hotel.
Pep is clearly a good manager at managing at high level, he is able to make well organised teams that play to their strenghts and is able to keep it going after winning.
But I've never seen Pep do something more than what he was given. His Barça team was stacked, his Bayern team was stacked, his City team is stacked, and he was never faced with real competition to his jobs there - when he did he most often lost.
Mourinho has won a lot of stuff but he also had managed to get great victories with teams that clearly weren't the best in theory.
So I have to put Mourinho ahead of Pep, Pep so far has been handed golden platters every single time and sometimes he squandered it, Mourinho had both golden platters and wooden platters and he managed to win with both (not always obviously).