So I just acquired a squire mustang with Seymour Duncan 4 wire humbucker pickups in it. It's has unusual wiring in it for a mustang. 2 typical dt3t but one is wired as a 3 way switch and the other as a rhythm circuit for the neck pickup only. I want to change the rhythm circuit to be a north/south coil split. What I would to know is if I can wire it so it will split both pickups with one slide switch at the same time. In the image above can you add the other pickup to the right side and it will split both pickups simultaneously? If so will there be any phasing or any other issues I should be aware of? Thank you for everyones time.