The only thing I would caution about someone wanting to play 'native' Au Ra is that it may come back around to bite you in the ass. The text is quite clear that as it says, "the Xaela are free spirits who roam the *vast western steppe*" Not, they're nomads that travel all over the world, but rather specifies a specific place.
I'm not telling anyone they can't rp a Xaela tribe that moved to Eorzea in ancient times past, but I'm warning you that it's highly unlikely that the lore will ever support you in that.
All in all though, whatever story you're using for your Au Ra, make it well thought out! Even if your story is similar to someone else, as long as you carefully crafted it yourself, why does it matter? Distinct =/= best. That's like me saying that my existence in real life is boring because I'm a white male from the United States. Sure, there are a lot of people like me, with similar backgrounds to me, but that doesn't make my story any less unique.
I'm not telling anyone they can't rp a Xaela tribe that moved to Eorzea in ancient times past, but I'm warning you that it's highly unlikely that the lore will ever support you in that.
All in all though, whatever story you're using for your Au Ra, make it well thought out! Even if your story is similar to someone else, as long as you carefully crafted it yourself, why does it matter? Distinct =/= best. That's like me saying that my existence in real life is boring because I'm a white male from the United States. Sure, there are a lot of people like me, with similar backgrounds to me, but that doesn't make my story any less unique.