Huh...that kinda reminds me how the Emperor in TTS described the Space Marines, Custodes, Primarchs and Himself: As the next Steps in Human Evolution, just created early through various shortcuts.Yeah, Like i said, we're on another level of hummanity, but we're still at the end of the day human.
Kinda like the ancient humans that are also a part of us in some small, strange and bullshit way, because DNA is a funny bitch that really needs to be not screwed with by aliens who want us to inherit the mantle of responsibility.
Still fundamentally Human, but...well, more.