How does each man's position fit his personality and ability?

First, it is clear that the captain, Jim and his men have courage and moral strength: they are able to win the battle and keep the stockade safe from the pirates because they do not back down even when their backs are to the wall and the situation looks bleak. In contrasts, the pirates seem slightly cowardly, especially in their retreat as one simply runs away in stead of being killed or trying to fight more. Moreover, they do not try a secondary attack with the men who have been firing from the trees - they simply give up in order to retreat and try again (assumedly) at a later date.