I have this problem too, both in this mod and in Europe 1805. To solve it, I do this:
At the start of each battle I press F5 (which is the "Hold Fire!" command), and then put my troops in position with F1. They obey your orders better that way too. When the enemy is within range, I press F5 again, to command "Fire At Will!".
(Many times I don't have enough time for this though, and I have to fight a battle with my band in a rather chaotic manner. Good luck in your battles!)