Kingdom of Heaven paid lipservice to Western Martial arts, but that's about all. Indeed, they didn't even pay to much attention to the story. The main charater of KoH was not at all how they showed him, indeed, he ended up in charge of the defence because he was the only Knight there, and he was there because he had specific permission from Saladin to go there to get his wife on his way home, and had promised not to be a part of the war.
When he got there, he found no one there was that age's equlivent of an officer, and took command. I've 'heard' that he wrote to Saladin explaining the violation of his promise, and that Saladin understood the nessicity and did not hold a grudge.
Troy was crap for the most part, but one thing I did like about it was that it was one of the very few movies where there was some attempt to maintain a sheild wall. Not much mind you, but some. One thing I HATE about movies is the 'crowds crashing into each other' approach. Like in Highlander 1, during the battle. He wanders around shouting 'no one will fight me? Why will no one fight me?'
If you were in that kind of thing, you run around stabbing the enemy in the back, whilst they are fighting someone else.... which is why battle lines are a basic idea. As long as you hold you line, you don't get stabbed in the back.
Japanese movies tend to be much closer to the Japanese idea of what would happen in a duel then any other's culture's movies, that's not to say they are spot on, but they are decent by comparicent.
But I will say using the sword in both hands was not unknown in the age of the shield. We have quite a few images of a shield fighter facing a fellow with a sword in both hands, and his own shield slung on his back. Also, in the Icelandic sagas, there are accounts of a man taking his sword in both hands. That said, KoH tends towards using (as far as it used anything at all) material on the Longsword, which is a different weapon then the singlehand sword, as it's longer, (allowing for counterattacks with oppisition) and has more room on the grip.