Yes, the White Glove goons that are sent to the room are meant to be hostile, because they’re trying to take you out before you reveal their scheme
I’ve done multiple play throughs of this quest and I’ve never had the rest of the White Gloves turn hostile after I killed the goons. You should be good to kill them without causing a massive fight. After that, you should be able to finish the quest by following the game.
Also my favorite way to complete the quest is to swap out the human meat dish with an imitation meat pie and then have Mortimer expose himself