the steel javelin if put into thralls hand disappears from view.
1 put it into there inventory as only weapon
2 get into combat
they take out javelin and use it during combat but it is invisable
issue 2 with thralls and steel javelin
1 put steel javelin into invetory
2 move steel javelin to main hand
the javelin will just disappear from game world
update i re logged into game world and the thrall was holding two weapons in his hand I had to unequipped both spear and the javelin that i put into his hand before logging out.