This quest really irks me. I thought it was common practice to give a good ending option in most quests; this one doesn't seem to.
I have a choice between slaughtering the druids defending their island from ones who would destroy nature to reach their ambitions or between slaughtering all of the Royal Deadfire Company - a faction that has given me a companion and that probably has lots more quests ahead.
I don't have an issue with choosing between factions but giving me no option but to kill one or the other... meh. This quest sucks. I've decided to skip the quest but that really irks the completionist in me. I like hard decisions but these are just bad options. I don't want to have to choose between my principles and my ability to fully enjoy the game.
P.S. I have used the Unity Console Mod to see if any of the speech checks I wasn't passing would have made a difference but no, there is no peaceful solution.