It's not the same because if you knock out someone during battle there is a reason you were battling in the first place. The dialogue should reflect that, otherwise it would be just as useless as it is now.
Take the tiefling and prisoner example. I fail the persuasion, I fought them and I knocked them out. What happen the next time I see them?
Fair point. You could have specific dialogue for NPCs you actually have encounters/dialogue with, and generic dialogue for generic one-liner NPCs? This would require work, but I think it'd be well worth it.
Tiefling example: In this case they could actually use the line generic NPCs would use: e.g., "Woah woah, my mistake. You're way to strong for us to fight."
It would be
cool if they specifically mentioned what happened, e.g., "Hey, where did the goblin go?" or "You're really brave/stupid to put yourself in front of my crossbow for a lowly goblin, why would you do that?"
But a specific dialogue line isn't necessary. I'd rather generic post-knock-out dialogue for all NPCs than either no dialogue or knocking-out not having an effect.
