Lone Wolf is for second playthrough and for experts that know all of mechanics ingame and archer is the weakest class in my opinion.
Try to max Loremaster early with one guy so that you can see resistance of your enemy.
Max one char on Crafting for better weapons, arrows etc.
Buy "shield"- and "immune to X-Effect"-scrolls and special arrows of the four elements. Piercing sucks really against skeltons etc so use a lot of special arrows.
Make one char more tanky and choose for the other glass cannon so that you have more action points. Dont resist to flee if the fight looks bad.
And dont forget that one or two level make a big difference in the game.
