Remarkably, the main characters are not the general and the princess, but two weak-willed imbeciles who comically derail their plans. By emphasizing the discord that accompanies even a few participants when they try to accomplish a goal, the film represents just how complicated it is to achieve broad-scale objectives when temptation, discord, and personal desires can derail even the most straight-forward of plans. Why display such pitiable characters so primarily? Maybe it's because that is the way we are: both clever at times, and stupid at times (a point presented nicely, although in a different context entirely, in this Jon Ronson TED talk). It's hard to admit that we can be our own worst enemy and far from the ideal heroes epic films typically foreground.
The Hidden Fortress (Kurosawa, 1958)