My knowledge of how coding works is null, so maybe this isn't possible, but I think it would both be themely, allow big chances for gang activity and vultures, and not shut down the MOO every time a fight pops off.
Kensuke walks in from the east.
Kensuke takes in the area, nodding in approval at the bloodshed being spilled. [this is the NPC running some kind of check on combatants]
Kensuke shouts, "BEAT THAT ASS! SNAKES OUT HERE WITH THAT BITE!"