I wouldn't put it quite as harshly as Redeyes did, but in a game as complex as Dom3, statistical risk usually takes a backseat to real uncertainty. A pretender is less likely to be killed by something you anticipated but dismissed as unlikely (the fluke attack that blinds and cripples your pretender so the chaff can swarm him) as by something you didn't realize existed ("I didn't realize fatigue allows critical hits which halve Protection!" or "I had no idea the enemy was going to spam me with Living Water from a W9 caster").
Creating a new game is a completely fair thing to do--call the prior one a "test game" which ended up teaching you some new rules. And don't use the Unquenched Sword or Rigor Mortis in any battle where you have units you can't afford to lose, unless you have some way (e.g. Fire Storm) of guaranteeing that you won't lose. And even then, be prepared to be wrong.
-Max