What was the thought process behind Shinovar being so similar?
A couple of reasons. One is, by having some sort of Earth analogue on-world, I could give some contrast, and I could have a kind of an explanation for why they might use words like chickens and things until I can get to the big reveal. Like, if there weren't Shinovar there to act as a red herring, I think it would give away the twist very early.
Beyond that, I like the idea of the people that are like us being the alien ones to the society. Kind of helps separate it and make it this is a different world, this is a different culture. So, it gave me a lot of advantages. Plus it also gave an explanation for how they could-- humankind create a foothold on this planet after coming across. So, lots of different thought processes behind that.