Asterisk 16 and server replacement

Following up on Matt's post on the ViciPhone v3 release announcement, he stated that Asterisk 16 is ready for production use and can be switched to. My question is, do all agent servers in a cluster need to be running the same Asterisk version, or can we have a mix of 13 and 16 running at the same time?
Slightly related, if we do need to keep everything on the same version, I have some ViciBox v9 servers that only support 13 that would need to be upgraded. Is there a process for replacing already existing servers in the system? Can I just wipe the drive, install a new v10, and use the same server settings that were in place before and have everything get rebuilt once it joins the cluster? Or do I need to delete it from the Servers entry first and then set it up new?
Slightly related, if we do need to keep everything on the same version, I have some ViciBox v9 servers that only support 13 that would need to be upgraded. Is there a process for replacing already existing servers in the system? Can I just wipe the drive, install a new v10, and use the same server settings that were in place before and have everything get rebuilt once it joins the cluster? Or do I need to delete it from the Servers entry first and then set it up new?