I like the foot soldiers' spear. It looks like a sound design. Using the shear mass and weight of the spear, I think it may even be able to peirce the armors quite easily; it certainly can peirce one right through the cavity, the trechea area between the colar bones, and the abdomen (inorder to gut someone quite brutally).
This reminds me of the Roman pilums, except they are sleeker in design for throwing to maximise penatration of the enemies' shields and armors. From I can tell you by lookig the pictures of the basic design of the pilums if you throw it right, as the pilum is decending onto the enemies at an arc, it should pick up more speed because of the weight at the front. And the sleeker design allows it to peirce through the air as it travels. I think to throw the pilum correctly (according to my observation of the design) you should think as if you are throwing the metal ball and to try to throw it at the intended target. The ball is also there to add more weight. That's my two cents, so don't take my words for it.
