The previous response is correct - ISC by design doesn’t support creating multiple accounts on the same source for a single identity through standard provisioning operations. This is a fundamental architectural limitation of ISC.
While ISC does support having multiple accounts on the same source (you can see multiple accounts in the UI for one identity), the provisioning engine will always try to modify an existing account rather than create a new one when provisioning access. When ISC detects that an identity already has an account on a source, it converts what would be a create operation into a modify operation on the existing account.
The “Provisioning Criteria for multiple Accounts” feature in access profiles is designed to help ISC decide which existing account to modify when multiple accounts already exist, not to create new accounts. This is different from what you’re trying to achieve.
Your proposed approach of using a Before Provisioning Rule to add multiple create operations to the provisioning plan won’t work because ISC’s provisioning engine will still recognize that accounts already exist and convert those operations back to modify operations before executing them.
For your specific use case of needing ServiceNow accounts to match the number of AD accounts, you’d likely need to implement a custom solution outside of standard ISC provisioning, such as using workflows with HTTP actions to directly call ServiceNow APIs to create the additional accounts, or implementing this logic in an external system that ISC triggers through an event-based workflow.