I doubt Ove would be more powerful than Thor or Hercules, as they are gods of strength, more powerful than other gods that are their peers and family.
Namor does already have a weapon that is a counter to Thor's Mjolnir, the Trident of Neptune. He just never uses the damn thing. This is a divine weapon of great power which can even control the sea. Writers have been completely asleep on this for decades. (Why would Namor need HyrdoMan's powers if he already possessed the Trident of Neptune for instance) I mean, it's barely ever even drawn the same by artists because they have no idea of the importance and power of the weapon, it's just a gold trident to them. Imagine if artists drew Mjolnir differently on every cover and every new story arc.