I feel it is time to address a seemingly minor question: should you re-image your nodes when re-using them from an existing cluster? To give a better idea of a setup, think of a cluster with eight nodes, for example. You would like to scale down the cluster and re-use 4 of those nodes to form another cluster. You have evicted the nodes, and you could create a new cluster at this stage but let's take a look at the pros and cons of rushing forward.
Cluster creation does no wipe the system. All the files on the nodes remain as they are when you trigger cluster creation. That sometimes can mean issues with LCM upgrades or the cluster creation may error out. To resolve those issues you would need to find those files and chances are you would need a Nutanix Support Engineer to deal with that.
Some features introduced in software releases are only available if the version is a fresh installation rather than an upgrade.
Any networking changes you might need are easy to apply during the foundation process.
On the other hand, imaging takes a bit more time than triggering cluster creation command but does it, considering the overhead of resolving potential issues.
Hygiene takes time and effort but saves even more of both in the long run. Spend your valuable time on other things and start your cluster anew.
P.S. And don't forget to upgrade BMC and BIOS;)
Prism Web Console Guide: Modifying a Cluster
KB-2637 Cannot Create Cluster or Add Nodes to Existing Cluster