It's all about coil splitting. When you start connecting individual coils in series or parallel (as the PRS 5-way does), if one of the coils is a north magnet & one is a south magnet, the combination will remain hum cancelling. So, for example, if the coils of the 2 humbuckers are like this: S-N N-S When you connect the inside or outside coils together in series or parallel, you get 2 coils with the same magnetic polarity and you lose the hum cancelling. Now, if the pickups are like this: S-N S-N When you connect insides or outsides, they remain hum cancelling. Since using inside coils together & outside coils together gives the most difference in tones, PRS went with alternating magnets. Peavey does this in some of their guitars that have humbuckers & a 5-way, too. With Gibson, Seymour Duncan, etc. humbuckers that are S-N N-S, you could still choose to combine coils that are opposite magnetic polarity, but the difference between the choices is less dramatic. Where this matters for LP guitars is if you just want to have a switch that splits the coils on a LP, I would suggest splitting to the front (neck side) coil of the neck pup AND the front (neck side) coil of the bridge pup, as well. That way, you will have a south magnet & a north magnet in parallel in the middle position & it would still be hum cancelling. I prefer the sound of the forward coil of the bridge by itself anyway, so that's a double bonus.