It guess it must match fairly closely to a '51 P pickup, but it terms of overall tone and output?
I tend to agree with the sentiment 'I can't see the logic in changing a bass with its own sound to be more like another bass'. Where I think the Mustang differs is that it is basically configured as a smaller P bass, albeit with slightly different pickups and body shape. A splitcoil pickup in the mid position is always going to deliver a P-type tone. I'm after a Mustang partly because it sounds like a P but is smaller, lighter and a bit easier on the hands. As I said before, I'm just shy of 6 foot, and I still wonder at times why basses have to be so big!