Alternator Stator Question

I was examining an alternator stator and wondering if all the copper outside of the laminations serves a useful purpose other than making construction easier. Would rewinding improve efficiency?

In theory (at least according to some descriptions I've read) all the copper on the sides doesn't contribute to output, and therefore should be reduced if possible. You could rewind it in a 'salient wind' configuration where each pole has a separate winding instead of overlapping 3 poles. I'm not sure how much improvement you get out of this, but it's supposedly somewhat better. It will change the magnetic configuration and some change to the rotor will be necessary (like more/smaller poles).