So last night I was farming butcher, i started in Agony 2:
Killed the first pack got 1 stack
Second pack, 4 teleporter, killed 1 and died, went back managed to kite one off on his own and killed him- I looked and I had 3 stacks of Neph Valor. Killed the last 2 mobs and it went upto 4 stacks
So 2 packs gave me 4 stacks? Has anyone else seen this, was it to do with teleporting out of range of the other mobs within the pack)