If Itachi protects himself and Kakashi in Susano'o, then they'll be able to snipe with genjutsu and ninjutsu combinations. Tsukuyomi can bring either of them down instantly if they look at Itachi's eyes, and both A and the Raikage have looked at the Sharingan against Tobi or Sasuke, and finger genjutsu combined with Kamui or Amaterasu can take either of them down as well. Neither have knowledge of his finger illusion. Minato and A are just so one-dimensional compared to Itachi and Kakashi.