What's your source? I've been to five of these places and whilst I would wholeheartedly agree that Pietermaritzburg and Durban should be on there (and I would add both Cape Town and Bloemfontein from personal experience as a victim of crime), I don't understand your inclusion of Napoli, Melbourne or Cordoba (Argentina), which seemed safe enough to me (especially Melbourne).
Im sorry, I thought they are dangerous since in Some wikis say naples are dangerous in Italy, Melbourne"s wildfires and others. And Cordoba being Random. I could replace it with Rosario and thanks for the suggestion of adding 2 more cities. Thanks