Bizarre pickup wiring help needed

Treewig1

I’ve got a new guitar with some really interesting splittable Porter humbuckers and a four-way blade.  It has a single volume and a single tone pot.  Neither are push/pull

There is no difference in tone between the 3rd and 4th positions on the blade and I see that the red and back wires from both bridge and neck pickups are not connected to  both, the green wires go to the volume pot.  The white from the bridge goes to the four-way and the white from the neck goes to the volume.

From my basic description, can anyone shed light on what is going on here?  How can I get a tribal variation from 3rd to 4th on the blade and what is this wiring configuration doing?

I thought I could sort this but it is a bit of a pile of spaghetti.