The Mourinho entourage as it arrived at Real Madrid was Mourinho himself, Rui Faria (fitness coach) Louro (goalkeeping coach) who've both worked with him for years, and Jose Morais who does the scouting reports on opponents.
He hired Karanka, an ex Real Madrid player who was coaching Spain's U15 team, as his assistant. He also asked Zidane to act as an advisor.
At Madrid, the only major coaching personnel change was that 6 months after Mourinho arrived, the reserve team coach got replaced. The reserves subsequently went on a run that took them from bottom half of their division into a promotion playoff place.
There will be changes at United, whoever comes in. Older team members will retire with SAF, some of the younger ones may feel their ambitions are best served elsewhere. What doesn't happen with Mourinho is some kind of clean sweep. Incidentally, I don't think any experienced manager travels alone.