In regards to that last female future-soldier model, I think a few modifications would help the overall form
- Study the length of her legs.
- Her lower stomach is in the wrong shape. It needs to be more curved to the likes of an athletic female. Do some anatomy study on this.
- Take a good look at her thighs, they look very chunky and fat. They are too thick, if you look at the concept they are much more athletic.
- The knees are too chunky (this goes along with the thighs)
- Her biceps are too small.
- Her breasts need more upper smoothing. In the concept they are smooth and sleek, they dont directly come out like a sphere. I think they are slightly bigger than the concept.
- Her shoulders aren’t as wide as the concept (Even though the concept is anatomically incorrect)
I think you need to pay more attention to the overall form of the character. The basic standing pose of the concept is very much like the pose of the following character by Hoshi:
http://www.zbrushcentral.com/attachment.php?attachmentid=263829
Other than that I think you have full sculpting capability to make this thing look awesome, just needs some form tweaking before you continue onto the detail.