Archers seem under powered. I’m not entirely sure what they need. Perhaps more work in the skill tree (more on that later). During tougher battles, even with the Sunder skill, they’re basically worthless against anything wearing chainmail or heavier. Another thing I have noticed is that enemy groups won’t advance on you unless you have archers. So having archers forces the AI to think “oh shit I gotta advance” and run right into your field of fire.
I’ve been running four archers in my party and while they’re painful to level up I feel they really take off once you’ve got them leveled and have some bow skill on them. Four archers with high bow skill and the berserk perk shred enemy forces. Generally I’ve been trying to run a front of six spears&shield guys with archers behind and 1 greatsword on either side of the archers for if the enemy tries to flank around spearwall and I find it works very well. Basically I use the spears to tank while the archers kill everything and have the two handers focus down anything that manages to flank around and get my archers in melee. Also, giving archers quick hands and a spear (I always go with spear for the +20% chance to hit) usually allows them to finish off a weakened enemy in melee if necessary and swap back to their bow. They are weak against armor, but I’m hoping higher tier bows might fix this in the future.