Honestly, I think Galateids are an interesting thematic point. Each of the (ugh, what's the jargon) bestowments (?) is an answer to the question "What is the motive that would cause you to create life?"

The answers given are
As a child- Frankenstein
As a slave- Tammuz
As a lover- Galateid
As an appeasement- Ulgan
As an idol- Osirian

The Frankenstein "Spurned Child" theme is at the very heart of the gameline, but I would say Tammuz and Galateid are both quite fundamental too. As derivations of the theme, it would ring a bit hollow if they were left out.