Certificates belonging to multiple users in a single token (USB) [on hold]

I am Testing an application which generates Security Certificates and copies the certificates to a USB Token. These certificates will be used by the end users to enable them access Remote Equipments.

There are no elaborately defined requirements for the Project.

The application currently allows certificates belonging to multiple users to be copied to the same USB Token. Is this the right behavior or should there be a restriction imposed, so as to copy only 1 user's certificates into a USB Token