Hello historians!

I just watched the film Glory (1989) for the first time a couple days ago. While I enjoyed the film a lot I couldn't help but notice the strategy used in combat or what seemed to me as a lack of strategy at all.

We see troops with their muskets and bayonets lined up in a row walking up to the enemy line which is in the same formation. No one tries to find cover or use protective gear of some kind. They just walk up to each other and start shooting and it seems like the side with more soldiers (or who can reload faster) wins. Also we see a fight scene in a small forest where troops are lined up again as described above. They all load their weapons but don't start shooting immediately but rather wait for their commanding officers command to aim and shoot. Then all soldiers reload and wait for another command to aim and shoot although the enemy line is what looks like 30 meters in front of them.

My question is how accurate this depiction is to real fight strategy from the american civil war era and why soldiers would wait for a command to shoot and then shoot all at once.