So, both basically have the abilities to one-shot (Mind Control daggers, Hamon + AP), and they both know this. So chances are, they'll both be playing pretty careful.
They both basically need melee, but Joseph's immense height (6'5) means his hand-to-hand reach is around even with Clementine's reach + daggers... or it would be.
However, I looked at it again.
Clementine's battle stance is very low-to-the-ground, leaving Joseph's immense height at a disadvantage. So, Clementine actually has more range than Joseph.
Speed Amplification basically means hitting a ranged Clacker Balls will never land, and easily deals with skill. So, Joseph's looking like he's in a bad spot here.
...now, I came across the damning fact. Clementine's arrogance and sadism, plus prior knowledge. Combine Clementine's tendency to talk and tease with what I said earlier- "They will both be playing more carefully" -and Joseph will have time. Time he will gladly take.
Joseph will stall for time, and take some time to travel around and set up, say, a string trap. Then, when Clementine goes in, she'll be quickly ensnared. Worst case scenario for Clementine, she trips. This is very likely, given her tendency to lean very far forward and to the ground in combat.
She may cast a Martial Art to attempt to escape, but the battle is already over. Joseph will already be sending clackers, or a hamon blow, her way. With a final "Your next line will be "I'll show you why people fear me!", to yu!", Joseph will end the fight.
My vote goes to Joseph Joestar.
