There's a secret simple way to recruit Minthara without Genocide and without losing both Wyll and Karlach,
1. Send her to the Emerald Grove
2. Then go into Act 2 without going to the Grove, you'll later recruit her at Moonrise Towers.
There's literally no need for a petition for something you could already do in game.
I honestly don't know the answer to this, but don't you miss a ton of XP this way? Also the tieflings and their related quests are still dead, so you miss out on even more xp. Not that I think Minthara should magically be happy to turn on the goblins and join you, it just seems like this "neutral" path doesn't have anything to make up for the loss of xp and equipment (or even Minthara's romance scene, right?).
