What is the relationship between user, robot, and machine (modern folders)

Hellooo together

Can somebody help out to understand the relationship between user, bot and templates in modern folders environment.

Lets assume I have 3 separated machines. Each of these machines have a unique machine template. Each machine has uipath assistent running and a machine-key is set. There are 3 users. One unique user per machine. Each user has an account on orchestrator (local user) with the flag for an unattended robot.

So, we have a relationship between robot and orchestrator and machine template via the machine-key. What/where is the relationship between the users? How does orchestrator know what login suits to which machine? Orchestrator only knows the robot and its key.

Actually, we have a strange behavior here. If multiple machine templates are assigned to a folder, orchestrator does sometimes and sometimes not use the correct user login. (And fails)

Thanks in advance
Enrico