The nut is much narrower than the bridge, so the strings flare out as they move down the neck. String spacing at the nut is set by the nut slots, while string spacing at the bridge is (more or less) set by the saddles and baseplate. Typical Fender neck widths vary at the nut by 1/16" to 1/8" overall, but at the heel they're always 2 3/16", with about 2 1/16" usable. Since the heel is much closer to the bridge than the nut, the bridge string spacing has more effect on how close to the edges of the fretboard the E strings end up. "Vintage" spacing puts them very close, while "modern" spacing tightens them up a bit, giving you room to do a bit of vibrato action on the strings without pulling them off the fretboard.