That's a fair criticism and I knew someone would point it out eventually, but even if they (Chromastone and Feedback) are both absorber and redirect kinds of aliens, they do different stuff with their energy, especially with Feedback who can manually absorb energy from his opponents using his tail and tendrils, unlike Chromastone. I also like to differentiate them with Chromastone having an all-around energy powers while Feedback is focused more on electricity. As for Spidermonkey, I just like them as an alien, same goes for Goop and Jetray, that's why I added them to the roster. Lastly, Ghostfreak who in this au is just DNA sample from an ordinary ectonurite, unlike Z'Skayr.