One question I asked a long time ago, but forgot if I got a definite answer to was: When are the monsters' drop created?
It's relevant because if it's created during spawn of the monster, then it's no longer about killing as many as possible, but rather kill enough for a monster to spawn with the loot, then you'll need to kill the one holding it.
If its dropped items is calculated only when it's killed, then it'll throw all that out. Just kill kill kill.
The former would imply that someone's hard work farming would go to waste because a random person could reap the rewards of the constant monster spawning, and kill the lucky one with the item.
This is an interesting thought, I have once observed how in populated maps like Niff or Prison, I get rare drops more often than in God forgotten places.
But again, all of this is hypothetical. :x
Also dueting or partying -can- get me rare drops.