After System refresh in "Q" getting 123 Duplicate USERS

Hi Experts,

We have done system Refresh in Q with P backup.After restore

we have re-imported the USER MASTER DATA in Q.

After this User master data reimport 123 duplicate user entries created. In SUIM its showing 840 user entries,actual user master data is having 717 users.

Configured STMS, imported USER Master data in Q and done post-processing successfully.

Does SAP_USER profile overwrite the existing user data in the target system?

Please guide me to delete duplicate entries/help me to understand why the duplicate entries are created. Can I know how and when these duplicates were created.

Regards,

Amarnath