I'm trying to rebuild a set of SCCM servers.
Define what this means in technical terms please. Are you planning on formatting the volumes, reinstalling the OS from scratch and then restoring ConfigMgr? Or something else?
Also, what has led you done this path and to the conclusion that this is necessary?
The version of SCCM when I first built it was 2016.
There is no such ConfigMgr version.