Default Assigned Payroll on Offer

Summary:

The goal is to default the assigned payroll based upon combination of legal employer + exemption status. I was able to successfully trigger the rule for Hire & Add PW but unable to get this to trigger on Offer. Can anyone provide some guidance? I string pulling in the row related to Offer but that didn't appear to provide any additional useful attributes. I've also tried with and without using the action types. Ideally, I'd really like to use an object function that stores the mapping so I don't have to use a bunch of if/then statements. Bonus points if