Mostly true. I have always 2 archers as a minimum. One of them is the commander-rally man with armor penetration-tohit chance from offense, having sidestep to escape enemy zones, vampires do not scare him at all. The other one is the high initiative high fatigue no armor glasscannon with focus fire and frenzy. He can kill up to 5 enemies in the very first turn if lucky, averages around 3. He is not afraid of anyone either. All who come in close are clubbed to death with focus instantly, be that a mere bandit a werewolf or a vampire. The commander one having rally means I can freely move around him and pay less attention to fatigue of others while his 2 shots are worth considerably less than the rally horn. They both don’t like shields, but have the armor damage skill so only the real hard enemies are a moderate problem as orc warriors or leaders they go down in 5-7 turns. With skeletons their only use is to shot down any non skeletal enemy and destroy the armor of fallen ones. The other 1-2 archers are situational, trying new skill setups and they are the ones who die usually. They are the bait for ghouls vamps wolves etc. With medium armor and shields.
When the enemy clusters up is a want to scenario after the one when you have the higher ground. You don’t have to hit, just aim in the middle and some will get it anyway. The shielded ones are harder at least at start or without the offense tohit skill. With it the secound one is most of the time a garanteed hit. With a good skill setup your archer can be a mobile unit flanking and moving around shoting between your lines. This aspect is my favorite, I like the assaulting fast moving melee aswell.
The role of the archers deminishes with time, at the start they are a very powerful ranged unit when enemy has no armor and your guys are squishy sacrafices. They save a lot of brothers and win battles that would be lost otherwise. At mid without a concrete role they start to lose their value rapidly. They can’t penetrate shields or strong armor. At late they are 1-2 shoting an enemy of the weaker type. They are great against ghouls and wolves. I try to use them to snipe the enemy range units or fleeing ones so I do not have to case em for an other 10 minutes. For now.
It is quite satisfying when you start off in row and explode into movement, intercepting incoming enemies with your line fighters and surround them with archers and light assaults. It is not an easy task but satisfying as whatever you like the fourth most.