-Trumps in CQC due to Enma and clones.
-Trumps in mid-long range due to his elemental variants.
-Can dismember her if he coats his Shuriken with Fuuton or Raiton, something characters inferior in power and Ninjutsu mastery and chakra control have done. That also helps him in CQC.
Tsunade literally doesn't stand a chance in hell. I was being generous when I said mid-high diff. Considering Tsunade only stands a chance in CQC due to her super strength, while Hiruzen can easily fight from any range and has the capability to end her regardless of Byakugo, it's safe to say that he mid diffs her at the worst.