Just because the fight is optional doesn't mean that a nerf isn't needed. This is possibly the second fight of the game, and it's far too easy to get killed before you can react or heal. The difficulty curve should not be quite so steep as to make a near-impossible fight as the second fight in the entire game.
That's the thing. My experience seems to say that it isn't that near-impossible if you're smart about where you keep the sword guard. He can't strike you if he has to take more than like, 3 steps.
MAYBE I could see a damage nerf on the archer, but I'm not sure how one should be permitted to simply kill guards without consequences, especially as newbie adventurers. Why should your characters be on the same level as trained guards?
I think it teaches you something about picking fights: some people are just stronger than you. Enabling easy kills on some of what should be the strongest legionnaires is lame.
If you still insist on a nerf after all that, how can you reconcile the legionnaires surviving a moment in their two year struggle against undead and now orcs? It wouldn't make any sense. They were drunk but functional, not out of their minds.