Heavy hitters rarely get full credit for their HTH skills. It's just a comics thing.
That said, Diana is the one heavy hitter who often gets serious skill props. In theory, she should be more skilled than Shiva; and Diana is used to fighting without her powers.
That said, in practice, it would be close. But none of the other 'skilled' heavy hitters would do as well as Diana, including Orion, Hercules, and Thor.
She's one of the few heavy hitters who gets real credit for her skills in heavyweight fights. Typically, characters like Thor or Hercules or Orion may get lip service as being skilled, but you don't often see them beating characters significantly more powerful than themselves on skill. When Orion throws down with inexperienced Superman portrayals, you don't see Orion overwhelming a hapless Superman with his New Genesis King Fu. He should, of course. In theory.
Even rarer is for a super heavyweight to be shown as a match for street level HTH elites when the heavyweight is somehow not using their powers.
Granted, comics are inconsistent by nature, and there is some evidence of other heavyweights being granted street level props for their HTH skills, but I don't think it happens that often. It seems to happen a lot more for Wonder Woman than any other heavy hitter I can think of.
Still, she is not immune to the curse of being a top tier character. By rights, she should dominate Shiva, even with equal bodies. But I think it would be 5-50ish instead.