If this is a fight Koto shouldn't be included.
I agree, plus if Danzo could use Koto i think he would have done it on sasuke before getting killed by him.
Since Danzo has izanagi and can use it 10 times (i think), and Kakazu only has 4 hearts or "lives", this puts Danzo at an advantage right away. It would also make for a very long, drawn out battle.
That said, Kakuzu has shown some extremely strong techniques as well as the ability to combine different elements for outrageously strong attacks. however when he uses these types of techniques, he is more vulnerable to an attack as there are four possible targets instead of one.
I say Danzo wins this one. If not, kakuzu goes down with him.