As hilarious/frustrating as it is to be in a 4v2 setup, I wonder if there would be any call for a system that only allowed players to actually join Goblinball once another player signs up.
i.e.
Player 1 joins, but only is TP'd to the stadium once Player 2 joins in.
Players 3 and 4 are in the same guild, and queue up Goblinball for something to do, and are both ported in.
During setup, Player 5 joins, but is removed from the skirmish once it starts because Player 6 just got invited to Astral and rejected joining. He may or may not be awarded a small number of consolation emblems since he had to wait.
2v2 Goblinball match starts.
Or maybe something to warp some players to the stands in the case of wildly unbalanced teams. (4v2, 4v1, etc.)