Hello Patrick,
Thanks for reaching out to us!
It sounds like the root of the problem is that users aren’t entering an “Organizer Name” but just an email for the organizer. This causes a new organizer to be created whenever they submit an event. You could pursue some customization which allows the email address to be the identifying key and doesn’t allow multiple organizers to have the same email address value. However this would be beyond the scope of customization that we can really provide in support.
As a solution, you could modify the organizer module ( views -> community -> modules -> organizer.php ) using our Themer’s Guide and have the dropdown of existing organizers check to see if the user’s display name is added as an organizer. If so, automatically select that Organizer. If not, autofill the “Organizer Name” field with the user’s display name.
I’m sorry I wasn’t able to give you a direct response however I hope this was able to point you in the right direction.
Thanks!