DOA characters always had some of the highest polygon counts in the business (except for male bodies in DOA5), wastefully high actually. You don't even need that many polygons to make a face look good as you can see on the MK11 comparison. And while they pumped insane amounts of polygons in faces and hair in DOA6, they reduced the polygon count elsewhere on the girls' bodies. As I said, that doesn't necessarily have to be a bad thing, as you can have good results with lower polygon meshes as well, if you do it right, but the low polygon angles have unfortunetaly really become noticable on the girls in DOA6, especially on shoulders, legs and feet.
It's once again a sign that whoever worked on the DOA6 models worked very inconsistently and ineffective.