Single renders get rendered per client, i.e. a single render is not shared across multiple clients. I thought it may do this when I first tried it but no, if you have five clients each set to receive network jobs and you set the queue manager on the sixth machine to send network jobs and then add a job, it'll just get sent to one client for processing, the others will sit there waiting for a job - they don't help.

Fine for animation rendering but doesn't do much other than free up the machine you're working on if just rendering single scenes.