Tombstone really falls down in this arena. Historically, Josephine Marcus, Delany's character, is reputed as a showbiz tramp. Many feel that she seduced Wyatt, leading Wyatt's wife of the time, Mattie Blaylock Earp, to commit suicide. Delany proves far too prudish to imply even more than a junior-high crush. But westerns have never been great romance films.
Tombstone is fairly accurate historically.
The Shootout at OK Corral is portrayed almost exactly as courtroom proceedings have described it. The Clantons and McLaurys were deadly rivals of the Earps, and this feud caused many casualties on both sides. The Earps were no angels, and I think that Jarre's script does a good job in getting that idea across. If you have not seen this movie yet, please make tracks to your local video store. Tombstone is a masterful blend of history, action, and wit.