People gravitate to one or two faces every time. Because those are the attractive ones.
Add sliders.
We really have no idea if that is true or not. I'm sure Larian has the statistics of how often each face is used . . . and if some are never used they will replace them.
I've played with 9 or 10 different characters and used different faces for all of them . . . including some of the 'less attractive' ones.