Those units do not have javelins on the model, but that`s not what is causing the CTD I think. The problem is that in descr_model_battle they do not have the proper skeleton/animation. You`d need it to look something like this:
Code:
skeleton fs_javelinman, fs_swordsman
Presuming they are swordsmen. If they use a spear you`d need this:
Code:
skeleton fs_javelinman, fs_spearman
The first is for the primary weapon and the second for the second.
The issue is that they will hold an empty fist when they were supposed to throw the javelins. But those will apear in the air after they throw them because those are taken from another place, not the model of the unit.