Artifact of Vengeance balance.

[Gummar]

One doppelganger is spawned for each player (two are spawned if the Artifact of Swarms is activated), when a doppelganger dies, they drop an item, this item is shared with all players on pickup. If there are eight players in a game. 16 doppelgangers will be spawned if the Artifact of Swarms is activated, each doppelganger will drop one item and the amount of items that will go to the player's inventories after picking them up will be 16 items for each player or 128 items in total. What I think that would be intentional in this kind of situation, is that only one doppelganger (2 doppelgangers if Artifact of Swarms is activated) drop their item for each doppelganger group that spawns.