I think it must be a pet peeve of mine, but I really hate when people compare Dark Souls to an RPG.
Dark Souls was action hack'n/slash roguelike with some progression and the most minimal story continuity possible.
That's besides the point. The point is that people get what you are saying, but nobody else who has watched that fight seems to think the balance is particularly off. A little better preparation, a little better armor/weaponry, a different approach and not presenting your back to the enemy. All of these things would have made taking on an enemy 33% of Geralt's own level higher than him, very very doable. Seems balanced.
I'm not really thinking of it as just this one fight in general, I'm sure I could take that guy without taking any damage at all. But think if later in the game you meet "random limp-wristed thug with a stick" and he will take 15 minutes to cut down because he has a ridiculous amount of health due to him being 10-15 levels higher than Geralt. Wouldn't surprise me if you will end up in situations where you will break 3-4 swords during a single fight if you decide to go up against higher level enemies. As I write this I realize that some of you live for this shit, whereas I think it's a boring way of implementing challenge.
I guess I can only hope that the game will stay balanced if I do stuff in a specific order, and that I can nerf myself by equipping low level gear later on. But I really think that I shouldn't NEED to do that. The game isn't truly open-world if the level requirements/recommendations are too strict.
Why do You have so much trouble understanding the concept of balance in vast open world game without scaling? The world really isn't open in Dark Souls, so You clearly missed the point here.
Dark Souls is semi-openworld, from the beginning you can choose to go to undead burg as is recommended, or you could go directly to Blighttown, New Londo, The Catacombs which lead to Tomb Of Giants
But yeah, my point was more about the balance of the combat throughout the game, even though the example wasn't really the best. It really comes down to the fact that there are more examples of RPGs that do the same mistakes(in my opinion) regarding balance that is directly related to the significance of levels.