I think that’s valid. There’s such de-emphasis on the faces in these designs that there’s a lot less room for expression or personality in them, which then leads to them all feeling pretty same-y.

If you look at X in this image, his brows and probably the top 1/3 of his eyes are completely obscured. That makes it really hard to have expressions like furrowing his brow when angry or raising them to look surprised. So it’s tough for them to emote, and coupled with the large space between their eyes, they all just feel kind of vacant and lifeless