Slot apparently has a similar tactical approach to Klopp, so should in theory be more suited to their squad rather than a bigger name like Tuchel, that would rip the whole team up to implement his system.
There aren't that many elite managers about these days, so more and more teams are taking risks (like Arsenal with Arteta, or Spurs with Ange) to find someone. Look at Chelsea and the state that they are in despite hiring big name Poch. On the other hand, it could also back fire like Ten Hag at United.