Don't know if this has already been posted but in french castles (northern european i guess) there is no good place to put your archers on the walls. It's hard to get them on the walls period but even when I do they just stand there and don't fire a thing. Occasionally I can position them to where 3 or 4 have a good line of sight but that's it. The only thing I can think of is if Darthmod modifies the arrow trajectories to be too low, they can't shoot over the walls correctly (In vanilla they'd just shoot at a real high angle). This is an extremely frustrating bug because it is a huge disadvantage to the French and other European factions with the same castle design. You can see it to a lesser extent when you order your archers to shoot at a ram attacking a wooden-walled settlement- if the archers are on the walls right next to the gate most of them will refuse to shoot at it, unless they are further down the wall away from the gate.