RZ, RB & GX680; Leaf backs (and some others) rotate on these cameras, just like a film back.
The Arca Rotaslide adapter allows to rotate the back as well.
Be careful of quick answers.
Yes the RZ will rotate but it's useability with the leaf depends on the original mount.
I believe if you go from the mamiya 645 mount to the RZ adpater Leaf supports that but they do not support the H-1 to RZ adpapter from Hong Kong.
Before investing in any of these specialized systems, get all the information up front and in writing from the dealer or the manufacturer.
Find out shoot rate, if you have to wait for the back to beep before shooting, if it takes added cables, or even dual cable releases.
Making it work is one thing, but making it work continuously and stable is quite another.
Same with tethering, software and processing, to make sure the workflow is exactly up to your own type of production.
I know a lot of photographers and techs who have used or tried to use the RZ with a multiple number of backs and most seem to have issues.
Always find out how it works in your real world enviornment.