First: dedicated archer is a pointless thing, because there are enemies in game that are nearly immune to ranged damage and there are enemies that will slaughter back line characters.
That’s exactly why archers should be dedicated. Their only weakness are ancient undead (especially necrosavants). I just swap them out for dedicated melee from reserve instead of bringing half-assed hybrids into such fights.
On a related note, is it correct that “unknown” enemies in ruins are never ancient undead? Because that’s my observation so far.
Second: As soon as i am able, i tend to start recruiting backgrounds with both high melee and at least ~50 ranged skill at level 1. Usually its raiders. As i start getting such characters, i pretty much start increasing the number of people who carry ranged weapons as secondary. So ultimately i end up with 12 people who can fire a bolt or 2 worth of crossbow bolts (usually crossbows) in order to soften up enemies. Sometimes ill keep 2 bowmen to pick off enemy ranged units.
I just advance my non-archers in tight shieldwall formation (while leaving some shielded newbies as cover for archers). This seems to drop enemy hit chances to 5% or near, as I often see fights without single ranged hit from enemy. And that is despite practically not leveling ranged def on non-archers.
Trading hits with enemy using unskilled crossbows seems less attractive option to me… Unless it ensures that enemies always attack, maybe? (because they see ton of ranged weapons without knowing how bad are your guys at shooting)