Scenario
You have configured Exclaimer - Signatures for Google Workspace and defined a Content Compliance policy.
However, other Content Compliance policies have also been defined and you wish to prioritize the Exclaimer policy.
Resolution
Unfortunately, Google Workspace does not provide a prioritization function.
This means you would need to recreate all the Content Compliance policies in the sequence you wish them to be processed (policies are processed from top to bottom, in the Google Workspace Compliance section).