There's supposedly is a 3rd Au Ra clan and they're older than the Xaela and Raen.
Finally, I mention that in addition to the Xaela and Raen clans...there are rumors of a different, much older clan. (and...this is where Yoshi-P cuts me off).
https://forum.square-enix.com/ffxiv/...=1#post3550637

If they were to add new clans for each race then they should be different from each like Highlander vs Midlanders are, but that's too much work for them. Or maybe have different faces? I think Goesetsu belongs to an Othardian Roegadyn clan.

Otherwise, I'd rather have more customization for the races we already have