itachi has more genjutsu than just visual sharingan ones, he can capture jiraiya in one, and once ur in one, u might as well be dead, if everyone just going for kills ... there isnt going to be any one on one'ing in a team fight... itachi and kisame will play on one another's movements so oro isnt going to have a lot of alone time with kisame, plus even orochimaru will run out of chakra if hit with semehada ( although oro evading skills are godly, and probably wouldnt get hit by it)... i dont underestimate the sanin, i no that they are some of the most powerfull shinobi in the series, and gladly tell ppl how they could beat alot of ppl in different combinations, but the team of kisame and itachi is a bad match for them... when itachi alone is such a handful to keep track of, then u have kisame flying around throwing s class water jutsu's and trying to suck all ur chakra away... while having the stamina to resist even major attacks... orochimaru would probably last the longest out of the three but they would all fall to itachi/kisame....