I thought that might be the case. I appreciate the input, but for me maintaining consistency between the rules for PCs and NPCs is not a high priority. It’s more important to me to capture the feel I’m going for than to adhere to symmetrical design.
I don’t anticipate my players being out to kill the other adventurers, and they certainly won’t be out to kill the PCs. They are first and foremost out to acquire one of the three weapons, and secondarily to acquire the other two. One group will have had prior experience with the PCs and will be perfectly willing to cooperate with them on the condition that the PCs let them take Whelm. Another will be after Wave, and be initially neutral towards the PCs. Whether they become friendly or hostile will depend on how likely they think the PCs are to help them get it, and how much they trust them to hand it over. The third group will be hostile and do whatever it takes to get Blackrazor. These are the ones most likely to end up in violent conflict with the PCs, and getting Blackrazor is still their first priority, so they are more likely to try to hamper or incapacitate the PCs and get ahead of them than they are to kill them, unless it becomes clear that killing them will be necessary to acquire it, or to escape with it.This is why I said that party-v-party combats like these will be among the longest you'll ever run, because as DM you DO have to take the time to sort out what each NPC can and would do each time its turn comes up...and be merciless about doing it; as these NPCs are every bit as much out to kill the PCs as the PCs are out to kill them. Cutting corners will inevitably make things easier on the PCs.
I had just been hoping for a different reason than to maintain symmetry between the PCs and NPCs.