Fair enough, but let's remember, it's all about matchups. Moreover, I don't know where the myth that the Sannin were low level Jounin came from, this is based on people's opinions and perceptions (they weer around Kakashi's age or Itachi's age which is above low Jounin for sure). I believe they were easily high Jounin but as you say we all have our opinions.
Lady Chiyo was probably a poor matchup for him, as we saw through her battle with another poison user in Sasori. She very much held her own and Sasori is one of the stronger Akatsuki members. She was also quite efficient in dodging and ensuring she wasn't hit that much. If this is in water Hanzo takes this, his speed in water is so essential in giving him the upper hand. Kisame will have an extremely difficult time in landing any blows of some sort on Hanzo.
What will Kisame do against Hanzo's poison? Sure, it takes 2 days to kill but it offers very quick paralysis and even if Kisame was to defeat Hanzo, by opening his poison sack or pierce his stomach he will only be contributing to his own death. So this match cannot end in anything other than a Hanzo win or draw IMO.
