I voted the last one, simply because it makes sense and is actualy realistic. Killing officers, meh officer aim
Officer Aim makes for an interesting turn of events depending on which regiment it is.
Also, promotions are a good way to show recognition. However, Medals are useful to hand out when some members feel left out. Ex. a person who can only attend 2 events a week will not be giving an NCO/CO commission because of a lack of activity. With a medal system, they can still take pride in their battlefield accomplishments.