I wonder how "Natural Concept" would apply to someone like Capt. Kirk from the original Star Trek. I kind of doubt he could build a transporter from scratch, but he made use of it quite a bit.
Hawkeye of the Avengers could be construed as Natural Concept, I suppose, although he made use of tech arrows, a hearing enhancer and Avengers' Quinjets to get around.
Maybe WildCat of the JSA is a better example--just a heavyweight boxer in a cat suit. Except he got those mystic 9-lives after a while.
Very good guide for a specific character concept, and an interesting discussion.