B2B Live TBC 2.4.3

Aktuell verhält es sich auf B2B folgendermaßen:
Wird ein Mob gepullt, dann kommen alle Mobs infight, die in Reichweite dessen sind. Was jedoch nicht passiert, ist dass die Aggro gepullter Mobs weitergegeben wird.
Diese Mechanik hab ich als co-Aggro oder chain-Aggro gefunden. Entscheidend ist, dass die Zugehörigkeit wichtig ist, so pullen Humanoide nur Humanoide, Wildtiere nur Wildtiere etc über diese Mechanik

So lassen sich vor allem in Karazhan und anderen Instanzen verschiedene Mobgruppen teilen, die nicht geteilt werden sollen.

"If a player (Paula) is in combat with a mob (Commando), and Commando ends up within the aggro radius of a second mob (Security) that is currently not in combat, then Commando may pass on his aggro to Security, and Security will be added to the fight. Security will initially have a threat of 0 against Paula, but will still attack her unless someone else gains higher threat. Situations when this is likely to occur include Paula attempting to run from Commando, using [Fear] effects on Commando, rooting Commando and then repositioning poorly, or when Security respawns or patrols close by to Commando. "Fear aggro" is particularly common and dangerous in dungeons, since the fear direction can be unpredictable, monsters tend to be packed in clusters, and most will chase indefinitely. Any of the above are even more likely if Paula jumps up or down a ledge over which Commando cannot follow, forcing him to take an unpredictable path to pursue her.

Co-aggro is very likely to occur when the two monsters are of the same faction or creature type. A Bloodsail pirate will always co-aggro nearby Bloodsail pirates, but will probably not co-aggro a gorilla. NPCs that are friendly (green) to the player will never be co-aggro'd, but NPCs that are neutral or unfriendly (yellow or orange) - who would normally not attack the player for entering their radius - may be co-aggro'd. "
https://wow.gamepedia.com/Aggro_radius

"Aggro radius also applies mob to mob. A mob with hate passing through another mob's aggro radius will pass on hate or threat to the new mob. Thus the new mob will join the party and add to the combat.

This only applies to mobs of a similar type. A bloodsail pirate will co-aggro another bloodsail pirate within his aggro radius, but a bloodsail pirate will not co-aggro a gorilla or vice-versa.
    This applies even if the mobs would not normally aggro when their attacker stepped within their aggro radius (i.e. mobs whose identifying text isn't red). If your reputation with the Gelkis centaurs is merely Unfriendly, so that their text appears orange instead of red, attacking one will cause other Gelkis centaurs standing next to it to attack you also." 
http://wowwiki.wikia.com/wiki/Aggro_radius