Tips for dealing with the Forest Bandits' Master Archers?

[ostlandr]

Just had a visit from the Forest Bandits, and they brought their A game. Eighteen of them against ten of mine, which ordinarily isn't a problem when defending a strong position. Except when their archers started picking mine off behind the merlons. Not just wounded, either. Thwip- dead. Thwip- dead. Lost four archers dead and the other two seriously wounded before I could get them back inside. They did manage to take out one master archer, but there must have been another one- or just enough massed fire to sweep the battlements.
Any tips for dealing with this? With those odds, sallying out to meet them would have been suicidal. I have my production buildings (smelters, kilns, smokers, skeps) set up in a k1ll zone. Normally, my archers savage the enemy while they're happily destroying things, leaving them without enough forces to take the house. But if I play this one out (going to go back to my save) it's thirteen on four. Once they breach the door, it's over.
BTW playing on the higher difficulty setting.

[Bethinia]

I've been experimenting with a few of my archers shooting at attackers behind higher level windows and putting merlons in front of those windows. So far they've been hit minimal times with none actually wounded. This has been in multiple attacks on high difficulty with 20+ master archers. All enemy fire is directed against the protected archers first since they're the only ones I bring up. Once the enemy archers are fully engaged, I'll swing other archers into place on rooftop positions behind merlons that would ordinarily be much more vulnerable to counterfire from master archers. Since the enemy AI is already locked on trying to shoot my well protected archers though, they ignore this much larger second group of archers, meaning an easy victory. It helps that the entire area in front of my settlement is covered with a checkerboard of wooden traps and non-active pyres inside trapped pits that severely slows down the enemy melee and archers.