Its official. For a guy who likes to play with toy soldiers, I think too much.
Firstly thank you to all who have commented so far, There have already been some very interesting and useful comments and no useless ones. I'll try to get to individual responses later. To everyone else, keep 'em coming.
The difficulty of linking or separating the moral and physical aspects are as difficult when writing wargame rules as they are when dealing with day to day life. I was thinking I had that squared away but it appears that I don't really. For one thing, if hits are as much about cohesion as anything, what does the size of the unit have to do with it?
While thinking about things like dicing to separate physical from moral hits and dicing to convert hits to stand loss or dropping them, I decided I needed to refresh myself on actual casualty figures, something I have to do periodically because the information seems to get lost in my head. Obviously not a thorough study but a very quick check of a couple of easily reached books with casualty figures for about a dozen battles, a mix of the Peninsula, War of 1812, Sikh War, Mexican American War and American Civil War. Typical unit casualties seem to be between 10% and 20% with anything over 15% being considered heavy or very heavy. Individual units that suffered as much as 25% generally suffered some disaster at close quarters. Unfortunately, none of battles looked at included any units that had been wiped out or routed off the field and I didn't come across figures for any armies that routed off the field though estimates of Sikh losses pojt towards 50% probably more stragglers than dead and wounded.
So, if my standard units are 2,3 or 4 stands, rates of 10% and 15% don't argue well for stand removal even if you swell it by stragglers,those helping wounded, or shell shocked, etc but dragging a growing trail of hits around doesn't make sense either. This was starting to sound frighteningly like a complete rewrite from scratch, perhaps to something like the portable wargame or something with a boardgame like crt with defender retreat or something, so I broke for tea before I got crazy and spoiled something I like.
Upon reflection it seemed like I am faced with 3 routes:
1) try to fix thing to be as accurate as possible regardless of whether its fun or makes sense,
2) ignore it, make the game as much fun and as exciting as possible and stop fussing
3) try to be more creative and try to make things easy and engaging without being quite so dramatically and obviously wrong, but also without changing the current shooting and melee rules.
(OK, I may have stacked the way I presented those choices.)
Looking at the effect of shooting historically there seem to be 2 main types:
A slow drain of casualties from skirmishers, artillery and long range volleys. This seems to weaken a unit's resolve when the real attack comes but it seems rare to find a unit driven back let alone routed by this kind of fire alone.
Sudden, heavy casualties from a close range firefight or canister. This can repel an attack or force a defender to retreat or even rout though usually the bayonet or some cavalry are needed to finish that off..
This is where I used to like Morschauser's 3" 'melee' zone since it caught that difference. It just didn't differentiate between charges and close range firefights.
So what if a unit, regardless of size, had a morale of, lets say 2 for regulars which was the number of hits required to remove a stand all of last year (1 for militia, 3 for elites) This number of hits might disorder a unit. Hits would not be accumulated, they either disorder or they don't. It follows that a single stand unit can only disorder a regular unit if it has no negative modifiers or is part of a group. To prevent a group of small units being more effective than one large unit, all hits against a group would count against each unit, disordering or not vs its morale. Disorder would remain until a successful rally.
If a disordered unit received a 2nd disorder result, it would be forced back a full move, perhaps losing a stand as an easy way to mark a permanent reduction in cohesion. If preferred, the stand could be marked as shaken rather than removed. Similarly, a unit defeated in melee would lose a stand if enough hits were inflicted.
(for example a unit moves up to attack a battery of 2 guns and the enemy rolls boxcars for shooting. The unit receives 4 hits, goes disordered, loses a stand and retreats a full move. If it had only received 2 or 3 hits it would just be disordered, if receiving 1or 0, it would be OK.
What would disorder do? Like the current "defeated" status which it would replace, the only order allowed would be retreat or rally. -1 to all shooting and melee dice while disordered.
What about 2 units mutually disordering and driving the other back? I can't think of any historical precedent, perhaps no shooting should be simultaneous? A priority would be needed, stationary first, then moving second?
I think I need to test this, looks too simple, there must be a catch.