No guarantee that Mourinho wins the CL with either Barcelona or Man City, given that he wasn’t able to win it with Chelsea, including during his first spell there when they had greater spending power than any other club in the world, or Real Madrid when he inherited the most expensively assembled squad in history at the time with a 25 year old Ronaldo that had entered his physical peak in it (I believe that Ronaldo spent more time injured during Pellegrini’s 1 season there, than during all 3 of Mourinho’s combined). Real Madrid were easily the best team in Europe in 2011/2012, but Mourinho wanting to settle for a draw in Munich after equalising, and then play defensively after going 2-0 up at home in the 2nd leg, was costly.
He clearly could never win 5 league titles in 6 years at any club, as he wouldn’t be able last anywhere near long enough in any one role to put himself in a position to do that.
But he has ‘underdog’ achievements that Guardiola doesn’t have. Leading Leiria to their best ever league finish at the time in 2000/2001, and to 3rd place midway through 2001/2002 before leaving to take the Porto job (I think that Leiria were ahead of both Porto and Benfica in the league at time), with next to no money to spend, was outstanding. And as I’ve said before, at the time of the 2003 UEFA Cup final, his Porto team was built on half the budget compared to Martin O’Neill’s Celtic team, and during his time there, the transfer fees on player sales exceeded those on player arrivals. Even before we consider the 2003/2004 CL campaign, winning the UEFA Cup in 2003 with them was already a hugely impressive achievement.
But on the flipside Guardiola’s influence on the sport, even if we avoid overhyping it compared to figures from previous eras, has clearly been far greater than Mourinho’s. It’s also telling that when Guardiola left Barcelona and Bayern, I’d wager that most fans of those clubs wanted him to stay, and there’s an excellent chance that when he leaves City most of their fans will be pretty sad about it while most fans of rival clubs will be delighted. But when Mourinho has entered a full third season at any club and any big club, many of their fans have been relieved and happy when he has left.