I believe the reason is that Asuras are still “higher beings” similar to devas, but due to their war-like nature, they are less rational hence they are at a disadvantage compared to say humans who are more balanced. Animals, as Ven. Yin-Shun once explained, are subject to enslavement or exploitation, or life in the wild where survival is paramount. Thus it’s a comparatively lower state.

And, of course, thank you for another excellent post about your Tokyo travels!