Just because the article said it doesn't mean it isn't stupid.
What if the NPCs have healing abilities? Are the NPCs all automatically able to be healed, get up and keep fighting? Or do they die instantly, never having a chance to do the healing? That's a pretty big change in the challenge that a group of NPCs will present.
How about non-opponent NPCs? When the young noble scion the party is protecting gets whacked down to -9, does he die instantly? Does he last as long as it takes for the PCs to get to him?
How about for monsters with fast healing or regeneration surges? (Assuming that such mechanics exist in 4e--though if they don't someone will add them in by the time the second wave of expansions hits).
What it comes down to is this: You're going to have to go through the death and dying subroutine for every NPC/monster that you bother to resolve dead/dying status for in 3.x. (I don't know anyone--no matter how strictly they interpret the rules that keeps the party in initiative and rolls out every stabilization check for a monster who has no source of healing and no way to get back up in 3.x). And since the article seems to indicate that the status chart is more complex in 4th edition, it will be more complex and cumbersome.
And, to dignify the "going through the battlefield and stabbing downed enemies" line with a response, PCs will still be doing that. Absolutely and certainly. Why? Because NPCs might still survive using PC rules on the basis of "the DM deems it necessary." And the creatures that the DM is most likely to deem necessary are: A. the ones who are really annoying and dangerous to fight (again), B. the ones whose survival will have an impact on the plot, C. the ones who are the DM's pet NPCs--in short, all the monsters/NPCs any sane/rational players bothered to stab/coup de grace in 3.x.
That they've come up with a system where the mid-high level window is good enough that being left alive at 1hp is not a death sentence is a good thing. (In my Wednesday night home game, we've adopted a different solution to the same problem: death occurs at - (10+character level)). That the 3.x version of the system posted is unnecessarily cumbersome and inelegant is not a good omen.
Professor Phobos said:
Didn't that article specifically say you aren't expected to keep track of this for NPCs unless you deem it necessary?
If they're all important, named NPCs and it actually matters how long it takes for them to die, just pick an arbitrary number of rounds they stay stable before dying. Assume that they won't roll a 20.
Done.