I see how mixing up someone's settings would cause them to lose the battle, I think that was the whole purpose of an ambush. Catch them off guard. No time to set up lines. Why is this a problem? Have we not been looking for something that allows a realm with very few troops to gain an upper hand?
One thing that I would highly suggest for ambushes, the attackers gain no Honour or Prestige in the battle, where as the defenders gain more than usual for surviving it (if they do).
I fully agree. It is not honourable at all. If possible, you should try to hide your name as well.
To summarize everything,
1) Ambushers should be hidden from scout reports until they are revealed by scouts - with a certain chances.
2) Only a certain number of TLs can set up an ambush in the same region.
3) Scouts can reveal them without letting ambushers knowing. If the ambushing party doesn't leave the region until next turn, they will engage in a normal battle with lowered morale.
4) If ambushed, the defending force - randomly selected, and the number is decided by the number of the ambushing force - will fight in random settings with lowered morale, however, TLs with high enough leadership skill can avoid this.
5) The ambushing party gains no honour or prestige.
6) Names will be randomly revealed.