7th Sea didn't splash like, say, Vampire did when it come out. Splashy enough to get people outside of the RPG community playing. 7th Sea was a great game, but I don't think it made a lot of waves, inside or outside the hobby. Anyway...
Ars Magica is a flawed game in many ways, and it's not one I actually played a lot. However, it has two things going for it relative to this discussion. One, it's a game designed specifically to have magic users at the top of the pile, power and influence wise. Second, an interesting and nuanced magic system based on die pools.
I think there's two options to represent a brutal setting like RSB's. You can go with more detailed and mechanical set of rules that replicate the power differential and cheapness of life, or you go with a rules that are more narrative focused and let some of that power differential play out through the story rather than through mechanics.
Personally, I'm against RPG systems that regularly leave the fate of player characters in hands of a simple die roll too often.
You critically failed your shaving skill roll, you cut your own throat and die... You laugh, but this happened in a session I played in. I wish I could remember the system, it was a fantasy system based on % rolling. Huh. It'll come to me.
That's not to say that players shouldn't be able to die via game mechanics, of course they should - without risk there is no suspense or tension, but rather that up to a certain point, the narrative of character death should be something the player participates in. There are few thing less satisfactory in a RPG sessions that having characters die in unimportant encounters because of crap rolling. I'm not suggesting anything about the Runequest 6 either, I'm not really familiar with it, just talking shop in general.