@jpcapone Thank you for reaching out to us, As I understand you are looking for guidance on how to apply labels when there is over lapping of SIT (sensitive information type).
You can create a custom sensitive information type (SIT) that includes both SSN and Credit Card numbers. You can then create a label that applies to this custom SIT. When you run the AIP scanner, it will scan the files and apply the appropriate label based on the SITs found in the file. If a file contains only SSN, the AIP scanner will apply the label that applies to SSN only. If a file contains both SSN and Credit Card numbers, the AIP scanner will apply the label that applies to both SSN and Credit Card numbers. Reference: https://learn.microsoft.com/en-us/purview/create-a-custom-sensitive-information-type
I hope this helps! Let me know if you have any further questions.