Reminder. Tall f au ra already exist in game and appears to use an altered midlander model. She's the captain of the guard in Shisui of the Violet Tides. She's taller than my 6'5" f duskwight elezen, and possibly slightly shorter than a min height m au ra.
But they exist already in game. Stop saying the devs can't do it and it would be too hard. They can make a new clan if it's a matter of breaking animations.
Which by the way, Fran used a modified elezen model and all viera's models and derivative of hers. Many of the races use an elezen model (Ancients/Amaurotines, Garleans (and they also use midlanders), etc). They reuse models for one race for other races or to make a new race all the time.
It really isn't that hard for them to use Captain's model into a player model for a new au ra clan!
And if no new races then new clans would be the way to go!!