Hello DaveRig,
In principle, if you do not need to have both nodes working simultaneously with the client, it may be sufficient to use only two licenses:
start client (activated) and send the network processing to the server, deactivate the license on client, activate it on one of the nodes and run that node - it will join the started processing.
Later you can deactivate the license on one of the nodes to use it on the client's side.