There is an "official" translation of the LN at j-novel club. I would suggest the translators to use the same terminology (symbiotic faction -> cooperation faction, ponytail -> horse-head) for consistency. I put the "official" in quotes because in the end it's just another fan translation, it's just that the people behind it have licenses and the right to distribution from the writer, so the quality is not guaranteed. But as it's the translation the author has approved, I guess you should stick to it.