The Zoom plugin uses JWT credentials (account Owner access) to create meetings. When a teacher creates an activity, the JWT credentials create the meeting for the teacher.
So it's not that the meetings are all being created for the same users. The Moodle user's email address is used by default to match the Zoom user's email address. This all requires that the teachers and the account Owner are all part of a single "group" account, like an Education/Enterprise/Business account.
You don't need to use the "number of licenses" settings unless you have more teachers than Zoom licenses. That's mainly there to help move licenses around for institutions that don't have a good automatic or manual system for managing licenses.
So it's not that the meetings are all being created for the same users. The Moodle user's email address is used by default to match the Zoom user's email address. This all requires that the teachers and the account Owner are all part of a single "group" account, like an Education/Enterprise/Business account.
You don't need to use the "number of licenses" settings unless you have more teachers than Zoom licenses. That's mainly there to help move licenses around for institutions that don't have a good automatic or manual system for managing licenses.