I am a bit disappointed by the way the author is approaching those notions. It makes no sense for Halfdan and Thorfinn to suddenly talk about the use of sanctionned/unsanctionned violence and interdependence between groups og people as a way to avoid war. This is clearly the author putting ideas from modern history that only seem evident in retrospective. Same thing with Cordelia, they accepted to call her a woman far too easely, they didn't even really discuss her gender. The suspension of disbelief is broken, at least for me.
There are good ways to deal with those topics though! Thorfinn could have discovered the principle of interdependence during his trip that we didn't saw (fucking useless ellipse...) . He could have also met a transgender or a non-binary person in India, and developed his thougths on the subject over several chapters.