Hello John,
Okay, while Ken Hamilton's frankenstein "cut and paste" techiniques will work reasonably well if you don't want to be bothered with sculpting and anatomy, they are also a compromise. They will not necessarily result in accuracy. And, if the base figure you are working from has inherent anatomy problems, it will not alter these. In fact, in cases such as your seated figure above, it will exacerbate them.
This ancient Verlinden figure is a case in point. In addition to the odd looking "stovepipe" arms (which lack form or wrinkles inside the elbow where they are most called for) the collar and neck of this figure are misplaced. Your attempt to give him the hang dog body language has perhaps helped expression, but it has turned the figure into a truly frightening malformity apparently caused by a broken and elongated neck.
The problem here is a common one. Many sculptors make the mistake of placing the collar "on top" of the shoulders. While you can almost get away with this if the figure's head is upright, once you attempt to tilt it forward, the absurdity of this positioning makes itself felt.
In truth, the highest point of the shoulders is not some imaginary line midway between chest and back. It is properly, toward the backside, in alignment with the spine, which at this point is at the very back of the neck. The trapezius muscles, which form the crown of the shoulders, join together and form the back neck muscles. They tumble forward at a steep angle toward the collar bone.
This configuration means that the collar should be high at the back, The neck tilts forward from this point, EVEN when the head is held upright. You can see that the collar of this figure droops at the back and that the neck is stock upright. This is anatomically incorrect.
I have photoshopped this photo to show you how the neck should tilt forward from the back of the spine. This then drops the chin close to the collar bone. The figure's chin should be about even with the very bottom points of the collar on the original figure. This is how it should work and you can check this by observing yourself in a mirror. Of course, the collar will have to be eliminated and replaced with a new one.
I hope this helps!
Mike