How does each man's position fits in 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 contrast, the pirates seem slightly cowardly, especially in their retreat, as one simply runs away to avoid being killed. Moreover, they do not try a secondary attack with the men who've been firing from the trees - they simply give up in order to retreat and try again (assumedly) at a later date.