This is a very edgy suggestion, I realize that. I know it falls in close to "Better AI," and is very similar to this suggestion I made a while back, but it is a fair amount more reasonable then that one. And to me it dosen't seem like it would be that hard to add considering what has been added already. Here it is.
Firstly, the Halt/Ready horns of command should be spilt into two individual horns.
Then, a fourth "retreat," or "scatter," horn would be added. When blown, all hired units under that squadron would flee from enemy units and players, similarly to hobbits, until a halt, or a ready horn is blown.
Not only is this very accurate to real life, (and Tolkien's works,) but would be highly useful. When it is clear that a battle is lost, a player could give the command to scatter, in the hope of saving as many units as possible.
It may also be prudent, (if possible) to have a "Distance from player" limit for obvious reasons.
Also, having 4 horns in your inventory, plus weapons, food, and anything else you want could get difficult, so if by some chance this is implemented, it may be helpful to condense the four horns into one, on which the "modes" could be changed with a shift click.
Well, thats about it, if you have any improvements or ideas, please tell me in the comments, and I may add them and give you credit. If you like this, please "Kudo" and comment. If you don't, well I figured about as much. I count every day that this lasts without being shot down by an admin a victory.