* Was the big melee at the end necessary? I mean, the position the English had against the French was far too advantageous to sacrifice, considering the French's numbers advantage. Why didn't the English just stay at the top of the cliffs and just rain arrows the whole time?
** Because Prince John wanted to lead the charge, because all it would take is the French to start getting organized and getting some people up past the beach to start coming in from the archers' flank, and because war is not always fought in ways that seem rational to someone watching from the vantage point of a movie camera.
*** Any attempt by the French to flank the archers wouldn't have succeeded. Due to the, y'know, cavalry and foot soldiers who charged the beach simply staying behind and defending them.
*** War is also not an RTS game where you can deny the enemy access to a set of squares by occupying them with units that have +2 armor. Cavalry isn't really meant to stay stationary, and infantry doesn't stay stationary once it starts fighting. Combat would have caused the lines to start gradually spreading out, and eventually one of the waves of landing parties would have been able to drive a wedge up and around to the flank. John's charge wasn't necessarily foolish purely in and of itself, just far too early.
* Why did Godfrey betray King John? He was already the second most powerful man in England. What could the King of France offer him to beat that?
** Being the most powerful man in England as well as the second most powerful man in France.