I did another test tonight. I am thinking that this armature is a bit unstable and has some spring to it compared to a wire armature secured with epoxy putty. I may have to make an epoxy version of the same proportions and try similar tests to confirm which is more stable for movement.
With this armature, when you move any limbs or the head the torso starts trying to move with it and then springs back. The epoxy armatures for Vitruvius and Damocles felt more solid in that respect.