I feel like Larian should really add damage resistances to the tutorial. May people, upon facing the Imps, have wondered why they're doing so little damage to them.
That said, you should still never be dealing 2 damage if 6 is the minimum raw damage. Check the combat log to see how damage was calculated and see how the damage formula is resulting in 2 damage.
+1 to the tutorial idea. You are right. A lot of people complain about damage calculations. I myself wonder sometimes about all the numbers that flash before me when someone hits me. I'll see several numbers spring up and wonder how I'm still alive if the enemy took that much off. There are times I've seen something like two 8's spring up but my character took only a few points of damage, so I figured some sort of damage resistance was applied and maybe one number was damage resistance.
Either way, it's confusing. A Tutorial would be nice if it doesn't already exist. Haven't really looked.
Funny. Never considered checking the combat log either. I'll have to do that in the future. Most of the time, I just assume it's correct and don't care.