kalirion: You mean the old "Climb on a rock and hope you don't run out of arrows before they die" strategy?
Well, I suppose there's always that as a last resort, but I was referring more to the following: For trolls quickly get behind them, then stay behind them as they turn very slowly. It's easy to land blows in between moving to keep behind the troll; even the black troll can be taken down at level 1 using this strategy (although it will take a while). For dragon snappers when they close within a certain distance they'll perform a charging attack, which can be dodged with a quick backstep; two forward blows will connect with the dragon snapper and also cause it to jump away from you, again putting it at the distance where it will use its charging attack. Rinse and repeat until the bugger is dead. The vast majority of enemies can be taken on in melee without taking any damage if you take the time to learn their attack patterns and movements, and the proper combination of attacks, parries, and dodging needed to counter their attack patterns. Things only get hairy when taking on multiple enemies at once, or when facing the occasional enemies that aren't predictable (such as skeletons and skilled human opponents).
PS- the guy taking on the orc in the youtube video is using way too haphazard a method. Best way to take down orcs is to interrupt their forward slash with a sideways slash (which will cause the orc to then jump back), and just repeat this until the orc is dead.