[...]
It's very possible that Arvel's height is supposed to be closer to some of the shorter female figures in the Descent range. I don't know. [...]
Did you bother looking at the two pieces of artwork of Arvel, the previous model, and compare it to the artwork and models of other heroes?
Because then you'd know.
The difference in proportions between Arvel and the other women is not one you'd see in human beings. Taller people generally do not have much larger heads, hands or fingers. Differences in proportion between adults are generally small, and I want to stress that Arvel is an elf, to boot.
A female elf, previously depicted as relatively short and lithe, that is so big that she doesn't fit on her base, with a head, feets, hands and fingers larger than practically any human or orc male.
Next to the others, she looks very much like an civilized half-ogre.