simply because they sound and feel different from 42 awg wound pickups
43 awg pickups with medium 10k-13k tend to sound bright and thin and going over 14k makes everything NOT paf sounding
the black dog and neck cold sweat are 42.5 polysol and they already feel different from 42 awg enamel models
technically, the only difference between the neck cold sweat and the bridge riff raff is the wire
same dc resistance, short alnico 5 magnet, symmetrical coils
in the bridge, they share a lot in common, but the riff raff sounds vintagey and the cold sweat simply doesn't
and going up to 43 awg makes a lot of diference, specially considering you have to get the dc up to tame the top end and fill the mids back (thinner wire = bigger resistance = less turns = less bass and mids and more treble)
and the hotter they're wound, further they get from the PAF ballpark
using softer sounding magnets like alnico 2, 3, 4, "isotropic" unoriented alnico 5 will tame things down but still won't make a hot wound pickup sound like a paf wound model
a bridge abraxas surely has a lot in common with a mule, but just can't sound the same
the nailbomb also has something in common with both riff raff and VHII... it's a different sound, but you can tell where it came from
and that's why we have so many options
if hotter wound pickups could sound like a paf model just by rolling off the knobs, we wouldn't be limiting our guitars to low output models, as we could have a lot more versatile guitars with hotter pickups that could do anything
and obviously, there's a reason slash prefers the alnico 2 pros
