They aren't far in stats. I would dear to say they are kind of equal if I'm remembering well.

Hanzo ~ Mifune ~ FKS Sasuke 3T = Danzō.

So the difference resides on abilities, where Danzō destroys imo.

Hanzo has three things to fight. Poison, which isn't that good in a fight against someone who resets his own HP, as you have to hit him. Explosion tags, which is just a ninja tool not that effective and Danzō can push away. And his summoning, to use more poison.

Meanwhile Danzō has ones of the greatest Wind Style Techniques, being capable of repealing Sasuke's Susanoo, Jujutsus at contact to make the enemy waste Chakra or be paralyzed, and 10 reset buttons in case he is going to die.

What I think would happen is that Danzō would try to trade damage multiple times while healing himself, to have a secure win. Or, just use zoning, I think Hanzo doesn't have anything to win at large range.