Better Than A 3!
As others have said, this isn't as bad as the rating says. It's no Gladiator, and I tend to be generous to movies about subjects I'm interested in, but this is watchable. A rating of 3 is not something I would consider even watchable.
If you have absolutely no interest in this battle, history or historic battles in general, then I'd probably give it a pass. But if you like these things, watch it, if only for the sight of the Winged Hussars. I'd give it a 5.5. It can get a little silly at times, but worth it for the battle.