Winning Ligue 1 with a bankrolled PSG, Bundesliga with Bayern, La Liga with Real Madrid, Premier League with a bank rolled Chelsea.
Not exactly the toughest accomplishments. It kind of shows that he could only win the league with the best team in each of these leagues. Also he is the only manager to have managed all the top teams in each league, kind of half the reason he is the only coach to have won the league in them countries.
All it takes is for Mourinho to go to the best team in France and Germany, and Pep to go to the best team in France and Italy for them to have the same accomplishment, they would basically walk the league as it almost guaranteed as manager of PSG and Bayern.
Hell, if I managed PSG and Bayern I would win the league.
The only really great accomplishments from him are winning 3 CL titles and Serie A with Milan. The rest are mainly from him choosing the best team or the richest team or both.