Well, I'd argue for variance based upon GM discretion, but not full-on Hail Mary-level RNG. I think it'd be really stupid if, say, the entire party got crit to death in their first battle against low-ranking enemies. Of course, that's an extreme example, but I think that if there's going to be a level of RNG, it has to be scaled reasonably well to what's going on in the environment and not get to the point where it's just absurdity upon absurdity... Which, you know, with enough potential modifiers (so to speak), could very likely become possible.

I think that'd likely be the best possible compromise; I mean, obviously it's interesting if you throw a wrench in someone's plans, because let's be real here, things NEVER go according to plan. At the same time, though... I think there's a certain line that you just have to not cross, or else everything just comes tumbling down.