To be fair, I think this is a clear case of god not being omnipotent. There isn't even one only goddess, but three of them, all necessary to create the universe. And Chaos alone can't rein in her creations. It something that clashes with modern religious ideas about omnipotence, but wouldn't feel out of place in ancient polytheistic pantheons where deities were never supposed to be omnipotent, omniscient or omnibenevolent.
Wait, these goddesses have appeared in other works of his? The Dal-Young-verse is real?