Each Zoom account can only host up to 2 concurrent (or overlapping) meetings at a time.
If you try to start a third session while the other 2 are happening, you won't be able to start the third session until you end one of the earlier two.
In other words, if you are scheduling Zoom sessions for an event, you can't schedule 3 overlapping sessions under 1 Zoom account. If there are more than two sessions overlapping you would need to schedule the overlapping sessions under other Zoom accounts.
Alternative hosts do not matter. What matters is whose account the sessions are scheduled under.
Recommendation 1: The best thing to do is create a Zoom session under a different host for each time slot to avoid any overlapping issues where you can't start the sessions.
Let's say Jane Smith is trying to schedule sessions for a virtual event and this is the event listing:
|Time of session||Original host||Issue||Solution||Host account|
|Jane||Can't host a 3rd session||Jane gets scheduling privilege for another user and schedules this meeting under their account making sure they don't have 2 other meetings happening at the same time||Scheduling Priv 1|
|Jane||No issue. Meeting 1 is over.||Jane|
|Jane||Concurrent to Meeting 2 and can't host a 3rd session||Jane uses scheduling privilege for the second user and schedules this meeting under their account making sure they don't have 2 other meetings happening at the same time||Scheduling Priv 1|
|Jane||Concurrent to Meeting 3, 4, 5||Jane gets scheduling privilege for a third user and schedules this meeting under their account making sure they don't have 2 other meetings happening at the same time||Scheduling Priv 2|
|Jane||No issue. Meetings 1, 2, and 4 are over.||Jane|
Recommendation 2: Do not have sessions that extend past the base time slots. This makes scheduling simpler.
If you have any questions about scheduling Zoom sessions please reach out to email@example.com for assistance.
Check out this article about getting scheduling privilege in Zoom: Can I schedule meetings for someone else?