Hi Matthew,
One matter concerning civil war movies usually not shown is the great numbers of men present in various actions. Usually only a few hundred, up to a thousand re-enactors are shown at one time in current/past movies. Hollywood needs LOTS of extras to make CW films more realistic.
With that said, here is what I think they usually miss portraying in Hollywood. Much sybil-wah (thanks Gary

action was pure, 100% unadulterated AMBUSH! Large numbers of men on both sides, led by green or incompetent officers were marched into column directly into an awaiting and hidden enemies muskets. One well directed volley...Boooomblapbaboom; and three seconds later 300 to 500 men fell killed or wounded. (Sadly, this was the true "action" in many battles) The "wounded in mouth" scene that you described could (then) be nicely inserted into the following 'regrouping' action that usually followed.
I agree with Admiral--Porter; great actions of the war in Georgia could and should be included. The western theatre battles such as the forementiond New Hope Church, Chicamauga, Bald Hill, the 'Dead Angle at Kennesaw Mt., etc. This filming would be "new ground" in Hollywood CW films and very well received by people like us, IMHO.
I've always thought a good western theatre CW movie centering on Gen. P.R. Cleburne & the Union 'Irish' commander (whose name slips my present memory??) who fought each other frequently in the western theatre, would be great! Of course I'm starving for western theatre action, as if you couldn't tell! :-)
Most Sincerely,
Rob Adams