That is according to UK Sport physiologist Phil Johnson, who thinks Manchester City boss Pep Guardiola has got his man-management skills spot on.
Guardiola’s City are 11 points ahead of second-place United in the Premeir League.
The Spaniard oversaw a 2-1 win over Mourinho’s United in the first Manchester derby of the season two weekends back.
City are yet to lose this season and have stretched their winning run in the top flight to 16.
And Johnson reckons Mourinho is struggling to boost his players because he lacks the charisma of his managerial rival.
“Pep is his own man, and he has a clear vision of what he wants to achieve which he has always been able to translate onto his team,” Johnson, speaking to BetStars news, said.
“It all comes natural to him, it’s what he knows. His over-emotionality is a benefit to how he relates with people, but there are times it doesn’t work to his advantage and I think that needs to be contained.
“He works secretly in training so as not to give anything away – he’s a strategist, a perfectionist, he makes sure that whatever he notes, he attends to, or gets someone else to attend to it.
“Last season it didn’t work as well, but it absolutely has this season.
“He has this great charisma, and charisma isn’t something you can manufacture.
“Mourinho has lost his natural charisma and he’s trying to manufacture it, which doesn’t work for me.”
Guardiola and Mourinho both joined their respective clubs in the summer of 2016.
But while Mourinho won the League Cup and Europa League in his first season at United, Guardiola is yet to get his hands on any silverware.
One team that was tipped to rival City for the title this season – before their incredible run – was Tottenham.
Mauricio Pochettino is widely credited with taking Spurs to the next level.
And Johnson reckons Mourinho also falls behind the Argentine when it comes to communication with his players.
“Jose falls behind in communication sometimes,” Johnson said.
“He is incongruent, in other words his expressions do not express his feelings.
“For example, a face that looks like you’re deeply depressed and angry and then you tell people how happy you are about a 3-0 win, that doesn’t sit right with me.
“I think that might reflect some of the difficulties he might be having with strikers, who need support, like all players do.
“I think Mourinho has a particular way and I don’t think it’s working enough, I don’t think he’s as balanced as he used to be, whereas both these managers are self-confident and have a sense of personal connection that is very important, whereas Mourinho is more inconsistent with his emotions.”