I don’t know if I can answer this fully for you, but here it goes:
The Studio licenses are per machine, so you only need one for each installation I believe. (if you don’t use Orchestrator, I don’t think you need any Robot licenses - atleast that’s how it used to be)
The Robot licenses are per Robot in Orchestrator, but you can only connect a Robot to one user per machine at a time. So, if you have 3 users on 2 machines, you would need 6 Robot licenses in order to make effective use of the users. Additionally, you can use less Robot licenses (like 3 for example) if you plan to edit the Robot each time you want to change that Robot to a different machine and/or user, but this method can be very annoying and inconvenient at times.
Here is a sample of how my company has it set up currently:
The “Unattended” showing 10 of 10 allows us to have 10 Robots to run on a machine all at the same time. The “Development” allows us to connect a laptop or development environment to Orchestrator so we can get information from Orchestrator (like Assets) while creating a project (it also runs from Orchestrator like the other Robot license). “NonProduction” Robots are really just allowing us to use a Robot for testing that doesn’t interfere with the Robot users that run our already completely deployed projects. Also, I think “Attended” will be similar to “Unattended”.
There is another setting here:
That is for 3 machines for “Unattended”, so by changing the Runtimes , it will only allow that many Jobs to run at the same time on that machine.
But, most importantly, you must consult your Server admins to install the Remote Licensing feature that will allow more than 2 users logged in simultaneously (which is the default). Once that is installed, you can log as many users at one time as the server performance will allow. (keep in mind that Windows 7 and 10 most likely will not let you log more than 1 user at once without some workaround, so I’m mainly talking about Windows Server which can allow as many as you want)
I hope this helps answer some of the technical questions until you get a better expert to answer them.
You would probably get a better understanding of the licensing model from an UiPath rep.
You can also try the support line here: https://www.uipath.com/company/contact-us/contact-technical-and-activations