I have to admit my favourite moments are the absolutely horrifying ones... it's these situations where I find myself really able to empathize with the ordinary soldier in these wars.
-Roundshot (or two, or three, heck throw in a howitzer shell too) wipes out the entire line save for yourself and a few others.
-Well timed/placed volley by an enemy line decimates your regiment and destroys your chain of command. Meanwhile cavalry are descending upon your rear...
-Three enemy regiments appear over the edges of the valley you're marching through (to your left, front, and right), and proceed to fire at and charge you. The perfect ambush.