I understand your frustration with the force composition in Ultimate General: Civil War. While it may seem random which units are deployed in battles, the game's mechanics are designed to simulate historical accuracy and limitations faced by commanders during the Civil War. There isn't a direct way to manually choose the units for each battle, as the game determines it based on the scenario and army organization. However, you can try experimenting with different army compositions and strategies to optimize your gameplay experience. It's also worth noting that saving before battles and reloading to rearrange your corps is a valid approach if you want to fine-tune your force composition, although it can be a bit tedious. Keep exploring and learning from the tutorial series you found helpful, and don't hesitate to reach out to the gaming community for further tips and strategies.