I beg to differ, I am pretty sure it isnt just Hanzo that can give the title. Yes they were the first but more people know of the 'rank' now. Where does it say that a different leader of a different village cannot give it out?there is no way anyone can become sannin since Hanzo gave that title to tsuande, j-man and oro and no one else can
Sannin is not a ranking.It's a titled given to Tsunade, Jiraiya, and Orochimaru by Hanzo The Salamander.and is naruto at the level even though he hasnt been promoted that high lol