If it was so easy to "just knock out" a bunch of guards, there would be a whole lot less dead Garlean soldiers in the world. Why kill them, when we can just knock them out, especially knowing that most of them are conscripts who are just fighting to keep their families at home from being executed? Incapacitating without killing isn't that easy to do, especially when you're outnumbered. It's an overplayed and unrealistic trope in movies - and I'm not sure that it's ever been executed in this game, by the WoL or by anyone else. The only instance that comes to mind, at the moment, is when the WoL was knocked out with a drugged beverage, and that's really not the same thing. Are there other instances in-game where the WoL, or anyone else, has shown the ability to punch someone unconscious without killing them? An instance where they punch to kill, but the punchee manages to live anyway doesn't count (not that I can think of any instances like that, either).

The WoL and the Scions kept the option for violence in reserve until there was really no alternative, and then applied the minimum amount of violence necessary to escape Ul'dah - even placing their own lives at risk to do so. They did this because they knew their pursuers were pawns in a greater scheme. While there are other occasions where the WoL is dumb in cutscenes, I don't consider this particular instance to be one of them.