Wait. There is a way to have a single OS Install with at least one partition, usually in OS8 but it can be from System 7 to OS 9.

Set up an Apple Share server on the machine you need this done. Set up the number of users you want on the system, each user getting their own account.

Then its getting to set up Chooser to select the Appleshare Server on boot and turn on Users & Groups to log onto itself. The Users get their own desktops and though everything is on the same drive, things are put away in separate folders.