From my understanding Allan Eckhart was a fair and honest man. The reason he wrote two books about the same story "Sorry in our hearts" and "The Frontiersmen" was to get both sides of the story. The first was the Natives side of the story, the second was the white mans side of the story.
I have talked to the local Shawnee historian, and even he stated that Methoasa was not Shawnee nor Cherokee. He stated that she was traded to the Cherokee by some other tribe.
Also, I have searched every document I could get my hands on regarding pictures or paintings of Tecumseh and have heard over and over that there are no known pictures of him. In fact the famous 'painting' of him was done in the image of his nephew, Tecumapeas son. The nephew posed for the painting.
I don't know if any of it is fact or myth, I am always searching for the truth. But instead of people getting angry at one another because their facts don't match, I think it is much better to work together at finding the right answers.