From playing a couple hundred hours of Expert Ironman the results are a bit surprising but very clear.
A dedicated Archer needs 3 things
1. Defensive perks and stats, so he’ll actually live to see LVL 6+. Getting killed by the first couple Necrosavants or 2 lucky Crossbows will happen even despite that.
2. secondary utility, so he won’t be useless against Ancient Undead.
3. Damage Output.
The mortality rates of my archers are insane. 10+ Wolfriders, Necrosavants are bad enough. But what they really die to most often are just regular Bandit Marksmen and Goblin Archers. Archers don’t wear shields and are mostly limited to light armour and helmets, so they are easy targets unless you get them to 40+ ranged defense. Stats are mostly Range Attack, Range Defense and Fatigue, if you get a +1 for either Attack or Defense take the best roll out of Melee Attack, Hitpoints and Resolve. Perks:
Tier1 I’m always taking Colossus since it puts you from 2-3 clean arrow/crossbow hits away from death to 3-4 right away.
Tier2 is Gifted to get the extra Ranged Attack, Ranged Defense and Fatigue.
Tier3 goes to Anticipation, now your guy can comfortably outshoot Bandits.
Tier4 is Bowmastery for Fatigue management and to outshoot/match Bandits in Range
Tier5 Footwork to get away from Melee
Note: Necrosavants will still kill those guys in 3 hits and there is nothing you can do about it other than to hide them in the middle of your formation.
From there its up to what you prefer, you now have an Archer that won’t just be doomed to die sooner or later and 5 more available Perks to build from.
My personal favorite is Quick Hands, Axe mastery, Killing Frenzy, Berserk and Fearsome/Headhunter. I prefer my Archers with Long Axes and Axe Mastery so they can really speed up getting rid of Nobles, Ancient Undead, Bandit Raiders and Orcs even without any melee skill after running out of Ammo.
On Expert you run into 5+ Bandit Marksmen with Longbows and Crossbows or even more Goblin Archers on a regular basis. The only way to get through that more or less unscathed is either running 12 guys with 400+ combined armour and Battleforged straight into melee or simply putting up a shield wall and outshooting them until they decide to charge you. The game gets really hard if you try to run into someone sitting back having more archers than you, even more if the terrain isn’t in your favor. Never again am I fighting 20+ Goblins in a swamp.