I think the only scientific way to determine that is to have Diana fight Kory... in a giant bowl of Jell-O.
Don't argue with science!
(Power level-wise, Wondy'd get the edge, but for straight-up fightin' skill, that's a toss-up. After all, they were both trained from birth by warrior races. I think it would come down to who struck a weak point in the other's ridiculously skimpy armor first. Thus, if Diana wears pants, IT'S ALL OVER.)