If you are editing item stats, make sure you edit it both server side AND client side (if not, what you see ingame isn't going to be correct)
Another thing you could do for debuging damage is, add a temporary console write line printing out the attack calculation for archers so you can fine tune it.
Eg
Console.WriteLine("Arrow Dmg: " + W/e the damage variable is called + " Dodge: " + GC.Client.Dodge (again, w/e it's called in lotf));
or add w/e else you wanna check to determine how much to lower/raise attack
that sort of thing will cause it to print to console EVERY attack allowing you to see very easily how the attack is calculated and makes things alot easier to debug.
Temporary console printing = win