The writer of the article should do better research. He claims Russell Bufalino and Bill Bufalino were brothers, when if fact they weren't even related. According to Sheeran Russell did allow Bill to say he was his nephew, because that would give him more clout when dealing wiseguys supposedly..
It's the Daily Mail. They couldn't care less about the background of the Bufalinos. They're just trying to give a quick description of Scorsese's new movie to their readers.