Hi David,
The default allocation of s.camapaign variable is most recent (last touch) allocation. The last value in the s.campaign get credit for the success event.
You can change the allocation under STAR >> ADMIN tools >> REPORT SUITE >> SELECT REPORT SUITE >> EDIT SETTINGS >> CONVERTION VARIABLE >> CONVERTION variable..
You can change the allocation to first touch >> first value get all the credit or linear, each value get a percentage of the credit.
Best regards.
Alexis Cazes