MPCs do far more 'permanent' damage then you give them credit for.
The only MPCs at danger of dying are those without a survival mechanic. You can play them as well as you like, the fact remains, if you are caught in a bad situation you need to be able to escape. In Dougan's instance, he is obscenely fast due to some sorta speed stack. Speed is what helps lycans, but most are not monks. Vampire spawn just.. well... you need to bash their coffin after you turn them to mist. So, Vampires rarely "die". Sunlight works too, but no Vampire paying a ounce of attention will be caught by that or even near waking hours. This leaves Flesh to Stone, I feel cheesy just mentioning it, so there.
Anyway, this just further demonstrates how only certain MPCs have means of surviving their actual role. For every time a lycan named Dougan escapes from a band of peasants with flaming pitchforks there is another who is caught and put down. For every vampire spawn misted to float away into safety, there's a wight who's dropped on the temple dais. Of course you can play MPCs in a very careful and guarded manner, never setting foot in the bloated hub of vallaki. But this still sets two kinds of MPC... those who can survive a difficult encounter and those who cannot.
It's something that should be looked at, is all. That is, some manner of adjustment to the current MPC rules.