Bandits and Raiders seem to be a little wonky compared to what I remember back during Kunark.
The human bandits were the only ones that should drop sashes, and every weapon they would drop should be bronze. On the other hand, all of the casters and barbarian bandits should never drop bronze, and never drop sashes as well. Brigands could drop a sash, and would drop rusty and bronze weapons randomly. This is how I remember it.
http://everquest.allakhazam.com/db/npc.html?id=364
Lots of useful info in here. Someone posted, and he seemed to remember it almost exactly like I do.