unable to merge duplicate

Summary:

When a candidate applies using their e-mail it checks against existing e-mail addresses in candidate profiles, which for current employees would also check their company e-mail (if they have one) and payslip e-mail (again, if they have one). There are quite a few employees who either have not provided a personal e-mail for their payslip notifications or have not updated their payslip e-mail, so when they go to external career site to apply for jobs and enter their personal e-mail it’s not found anywhere in the system.

We already provided an explanation to the business but according to them, It’s not an ideal solution, as it requires the offer to be extended and accepted, then the candidate provides the sensitive information that allows them to verify they are a duplicate and when we merge the records the offer must be completely re-created in order to retain the ex-employee file. I want to verify this is the expected solution? otherwise, is there any workaround to merge the duplicated records without redrafting the entire offer?