Most of those noob mobs have an npc_faction id of 38, which is the standard faction for newbie zone trash mobs. It can be a benefit in "some cases", in various zones, you can run to the guards and they will kill the "38 faction" mob for you. It's not really a case of them assisting each other, most of them will aggro while you're already engaged if they are walking by, or in aggro range. One option, is going into the npc_types table and reducing the aggro radius, but that could have effects on pulling. Run for the zone line