This is a very common scenario. Teachers often create their accounts in Edulastic and enroll students before the district decides to perform Clever sync. Edulastic is designed to merge student and teacher accounts using their email IDs.
This implies that student and teachers can continue to use Edulastic with Google or Office 365 IDs even after Clever sync. However our automated sync process does not merge an existing class in Edulastic with a class present in Clever feed. Thus teachers who were using Edulastic prior to Clever sync will end up having extra classes as compared to Clever data. We recommend archiving of the classes once the active assignments are completed and flagged as "Done".
If its important that existing Class in Edulastic be merged with Classes in district SIS, please discuss possible options with Edulastic customer success team.