Well, as I said on a music thread a while back, "Gods & Generals" is exactly the kind of movie they'd have made in the 19th Century. Mainstream writings of the period are strongly sentimental, preachy, and idealistic, and they frequently urge the pursuit of honor and nobility on the battlefield.

There's a famous post-war quote from Oliver Wendell Holmes, Jr., a Union officer who was nearly killed in action in 1861, giving the highest praise to the "faith" of the soldier who gives his life following orders whose purpose he doesn't know in a cause he doesn't fully understand. (Like the Light Brigade.) It was not yet the modern world.

My guess is that the more you know about the Civil War, the more you'll appreciate the movie.