Then perhaps the in-universe justification for the Zodiac stations bearing that name might be because KFY had assistance from the NDI into fielding a different type of starbase other than the Iori type.
The thought of Kagami-based constellations makes me somewhat leery. The star formations named so far have mostly whimsical names that are hard to take seriously. I'd rather have astrological signs that don't belong in the Kagami galaxy than ones which go like "Sword", "Bucket", "Snot cloud".
Then again, the 'signs' may not need to be based on astrology. The chinese zodiac assigns a roster of animal, per year. So far, we do have Terran animals on Yamatai (or at least have made free references to them and their byproducts). Again, it can be something the Yamataians picked up from the contact with the Nerimians. The Empire is still not 40 years old, and it's very much like nekos to draw examples from humans. Yamatai also still has unmistakable asian roots, with Shinto religion present on Yamatai.
So, say the YE zodiac calendar puts the chinese leap year first, it would make YE 1 to 40 look like:
YE 1 Rat
YE 2 Ox
YE 3 Tiger
YE 4 Rabbit
YE 5 Dragon
YE 6 Snake
YE 7 Horse
YE 8 Goat
YE 9 Monkey
YE 10 Rooster
YE 11 Dog
YE 12 Pig
YE 13 Rat
YE 14 Ox
YE 15 Tiger
YE 16 Rabbit
YE 17 Dragon
YE 18 Snake
YE 19 Horse
YE 20 Goat
YE 21 Monkey
YE 22 Rooster
YE 23 Dog
YE 24 Pig
YE 25 Rat
YE 26 Ox
YE 27 Tiger
YE 28 Rabbit
YE 29 Dragon
YE 30 Snake
YE 31 Horse
YE 32 Goat
YE 33 Monkey
YE 34 Rooster
YE 35 Dog
YE 36 Pig
YE 37 Rat
YE 38 Ox
YE 39 Tiger
YE 40 Rabbit
Kotori's zodiac sign would be Tiger, because she'd be born in the Year of the Tiger, YE 27.
It's also a silly coincidence: Kotori's mother Kôsuka's samurai monicker is Tiger Mother.
YE 22
Yui: "You're telling me I should try this 'chinese zodiac' at home for fun when my sign is rodent vermin?"
Haha.