[servomoore]

I personally like the way that the artist drew them, but I've been told they look wrong, too flat for how large they are. Since this is being drawn as a promotional image, I do need some outside opinions.

The artist is really busy, but do you think it should be alright for me to ask her to redo them a a bit?

[Reaver]

It is a commission, then yes.  Otherwise let it go.

[pedonbio]

I'd say the left one (her left) is fine; the right one needs work.