Chariots do not have a separate Weapon Skill, so when they fight in hand-to-hand combat the enemy compares his Weapon Skill against that of the chariot's crew. If the chariot has crewmen with different Weapon Skill levels then he always counts the highest. If all crewmen are slain and you still wish to strike blows against the chariot, count its WS as O and therefore all attacks hit automatically.