We are not aware that there was a struggle on any of the other two flights. If they knew that they were going to die, I'm sure they would have fought off the hijackers.
As for the movie, its funny how politically correct the US is, getting hot studs to be hijackers. Of course most movies are this way but you'd think they would at least find some average looking actors since this is based on a true story.
On a side note, things can also go on the other extreme. When I was watching Bang Ranjan in Thailand, they got one of the most nastiest and ugly MOFO to play as the Burmese King.