Itachi and Kisame get vaporized. Samehada is not absorbing that for Kisame when he couldn't even absorb V2 Bee's Lariat fast enough to stop it from blowing open his chest.
-he has the speed to Evade all of their attacks such as totsuka
-he has the durability to tank all of their attacks comfortably
-his TBB barrage would destroy itachis susanoo and will overpower kisames GSB as well as samehadas absorption furthermore the attacks destructive scale is far too much for itachi and kisame here...