They edit hats/helmets sometimes to go around features like Au ra horns
https://i.imgur.com/HbNTMgH.png
Adjusted so the horns wouldn't clip; if you understand how it would clip how the female Roegadyn has it.
They could do the same edits on Viera hats (making them smaller/larger on Viera to work around things a little bit).
Clipping is not a really good excuse, I'd rather they say they don't have the time to do it than look for cheap excuses like "it would look weird on Viera heads." What looks weird to one person looks great to another. What's really bizarre to me is the Shadowbringers situation, they should've been adjusting those on Viera/Hrothgar, and stuff like Mogstation hats/helmets.