re: Gerald Kuiper
Yes, they were captured objects. Whatever changes they have had, must be one of a galactic chronological one (if I may).
Bottom line, know the geological structure of these 'things' orbiting our gas giants, even the odd ball Pluto.
My humble opinion, if it isn't terrestrial or gas giant in nature, it must be a captured object. Then, go from there, if you have to... as in (captured) moon or our transient Pluto.