Well it's not chess anymore, there's troop morale and morality in actions (or in this case, hotbloodedness!) as well! Lots of improvisation, and impromptu decisions, then we get to see their self doubt so I guess that accounts for something.
“I love heroes, but I don't want to be one. Do you even know what a hero is!? For example, you have some meat. Pirates will feast on the meat, but the hero will distribute it among the people! I want to eat the meat!” - Monkey D. Luffy