The game editor already supports 4 player co-op.
The main game stated off supporting 4 players, as well, but the 2 player-henchmen would not have been able to take part in conversations. With the added complexity of the henchmen and companions in the kickstarter stretch goals, Larian decided to focus on the two main characters for co-op, rather than half do 4 player co-op or double the amount of player dialog for the minority of situations where people would be playing that way.
