My rationale behind it for each team:

Pacers: Obviously sure up their center needs with a guy I think fits in perfectly. They won't pay Mathurin the money he will be searching for to be a super 6th man, but instead allow him to move on while using that money for Kessler.

Jazz: This is the last year Utah's FRP is protected so they will look to be a more competitive team next year. I think the shift to Zu allows them to continue that while also recouping a first for Kessler, and Zu is also on a great value contract for the next few years. This also helps further the development of Filipowski.

Clippers: If Harden does get moved, this move helps them shift to the future a bit. Mathurin is a guy who could easily be a 20+ ppg guy when given the opportunity. It allows the LA to retain him by giving him the contract extension he's eyeing. I also believe the ability to play with Kawhi could help his less to be desired defensive abilities, but who truly knows.

I would understand if others issues is with the picks. Would be interested on that Harden return if it happens.