Napoleon>Ken

Napoleon, without a doubt, did more damage to the Yanamamo. By giving them weapons and telling them to use it against their own people, he added this whole new element to their lives that can never be forgotten. Ken only affected one group of Yanamamos, not all. I think that Ken shouldn't have married Yarima if he wasn't willing to fully divulge into their culture. But overall, I think the emotional and physical damage was done more by Napoleon than Ken.