Complex sentence: Footmen also get a small sword or an axe, and throwing firepots, not deadly but usefull to blind whatever they manage to inflame, and since they continue to burn after having hitting the ground, they can help restricting access (ie a door entrance).
Split into simpler sentences: Footmen also get a small sword or an axe, and throwing firepots; not deadly, but usefull to blind whatever they manage to enflame. And since they continue to burn after having hit the ground, they can help restrict access (ie a door entrance).