Historical accuracy in war movies

[Tuor of Gondolin]

In the U.S. there's a series on the History Channel "History or Hollywood?" where movies are studied for their relative accuracy. What about a discussion of some such movies, how they shape up, where they're at fault, how could they be improved, what if you did a remake, etc.?

How about two movies, one good and one not: The Great Escape and Mel Gibson's The Patriot. I think the concensus on the Great Escape is that a lot of care was put into it (even filming it in Bavaria) with the chief change being that the American flyers, while they were involved, were moved out before the actual breakout. But since they were involved, and box office appeal is a big consideration, that was tolerable for me. Besides, you want James Garner and Steve McQueen in the finale, right?
The Patriot, though, had just too many unneccessary flaws.
Some of them are:
1) From the movie it would appear that slavery didn't exist in the American Colonial South (when actually many slaves, understandably, fought for George III in the Revolution).
2) The foolishness with Col. Banastre Tarleton burning a church and civilians , in reality he got the moniker "Butcher Tarleton" from one or two incidents of not preventing his men (perhaps they were Loyalists and not British, I forget) from killing American soldiers trying to surrender.
3) A botched Battle of the Cowpens. Perhaps to give Mel more to do the actual battle is reversed. In reality Nathaniel Greene and Daniel Morgan "The Old Wagoner" used the militia to draw out Tartleton's cavalry strike force and then crushed them between Continentals and a relative of George Washington's Virginia horsemen. Of course, in the movie it's Mel's militia that saves the day (absurd!). A key point that George Washington stressed and worked to improve was the need for Continental Regulars as the core of the American Army to field an effective force against British and Hessian regulars.
And while I've managed to partially blot out the memory of some of the Battle, I believe that in the movie Tartleton is killed. Remarkable, since he served many years in Parliament after the war. It would have been more accurate, and much more interesting, to portray Tarleton as sort of, to the Americans in the South, as Rommel was to the British in North Africa, a brilliant commander who was irritating mostly because of his use of speed and the tactical offensive.