Not taking out Paulie would benefit New York. He, i imagine, would probably be next in line if they had managed to kill Tony. And him not having the brains Tony has would mean he'd have no ambition and wouldn't try and get in New Yorks way.
"strange things happen all the time, and so it goes and so it goes. and the book says, 'we may be through with the past, but the past is not through with us'" - MAGNOLIA
