Just popping in because I just thought of a compromise I'd be fine with.

What if, for male Viera bodies, they simply reused the male Au Ra model, albeit without the scales and scaled to an appropriate height, but no other alterations; and then plopped unique heads on top?
This would do multiple things:
a) It would provide a slim yet strong build that the majority seems to be okay with, while keeping it somewhat unique
b) Gives us access to the truly unique feature of the Viera, the (most likely customizable) ears
c) Doesn't increase SE's workload by much, since any unique alterations would already be made for the Au Ra; they'd just have to scale it accordingly (which might even be automatable?)

They could do something similar for female Hroths, simply reuse the female Roegadyn model scaled to height and adding a fur texture, then put the unique heads on top.

Now, while this wouldn't be ideal, if ressources and workflow are truly the issue, I'd still be fine with this over getting no mViera/fHrothgar.
Of course they'd still have to put in the initial work for modeling the heads and making the animations, but adjusting existing and future gearsets would be far less grueling and ressource intensive.
Just something to think about.