So I just completed slaughtering all the druids in the druid grove (due to the death of the tiefling child) and I have some feedback.

Starting with the archdruid and the girl's death:
1. If I shoot the snake and kill it before triggering the 1st cutscene where the archdruid says to imprison the girl (and the girl dies if you don't convince the archdruid to stop), the girl instantly dies anyways. The combat log just says she "took a fatal blow", but absolutely nothing attacked her (and the combat log doesn't even say what hit her). This is super frustrating. If you really want her to die in this situation, either have one of the druids attack her, or have the wolf be close enough to do so (and have someone command it to). Or heck, even have the snake lash out in its death throes and kill her. Literally having her die for no reason whatsoever is terrible.
2. If you trigger the fight with the archdruid via cutscene, some of the druids run from the scene to go give the order to wipe out the tieflings. You are in TBM and they just infinite-move and run right past your characters or even through them. Again, this is awful. I understand the desire to have them go alert the others, but they should be constrained to moving in turns and being blockable/taking opportunity attacks as they try to escape. Give the player a chance to kill them and cut off reinforcements/protect the tieflings. Otherwise it feels like complete and total BS.

I initiated combat outside of the cutscene after letting the archdruid kill the girl. The npcs did not flee (and Nettie did not come out and join the fight). I was able to kill them all with a gratuitous amount of save scumming, but there were some problems.
1. The rats have abilities? One of them survived the opening of combat. She used ranger abilities, including hunter's mark. She was able to cast spells, and even use Entangling Shot. A: Rangers don't have wild shape; B: even if they did it wouldn't reduce them to 1hp; C: if they were polymorphed they couldn't use abilities from their base form; C2: if they were wildshaped somehow I don't think they could cast spells; D: If any of the previous were true there is no circumstance in which they could use a BOW.
2. Killing the rat caused it to become a person's corpse with 29hp, so it was obviously some form of shapeshift, but nothing makes sense (see above).
3. The rat (or whatever) climbed the vines to get high ground and shoot its bow/spells. It had no climb animation and so just hovered up into the air.
4. I used hold person on the archdruid (reloaded until it hit). Hold person says the target can try and break free at the END of their turn, but she saved on her turn then immediately cast a Thunderwave and then attacked twice in melee. Not sure what was going on there all told.

The biggest issue came when combat was finished. After leaving and going to the main area, there is no way to tell anyone you killed the archdruid, even though your quest log has updated to say you did. You cannot even tell the girl's parents you avenged her death. VERY unsatisfying, and definitely needs to be added.

I started combat with the druids in the main grove area. Once again a bunch of the NPCs ran off to go start fights with the tieflings, and once again there was no way to stop them because they ignored being in TBM (this time it didn't matter how I started combat, they always went running off.) Still a terrible idea. Needs to be changed here and anywhere else you use it. Make them move normally on turns and give you a chance to stop them, even if unlikely. Or have them move to sound some kind of alarm device. Anything as long as it follows the rules of TBM.

After fighting the druids, the tieflings thank you for standing with them but there is still no way to mention to anyone that you killed the archdruid. Plus a bunch of the tieflings are dead by the time you get to the top, which again is really annoying since the druids ran off to fight them ignoring TBM.

The tieflings won't let you loot the druids' corpses. The corpses are red and the tieflings tell you "hands off" if you try. Doesn't make any sense; they were mutual enemies and the tieflings obviously don't loot them. Went through all the trouble of getting rid of these jerks, should at least be able to take their stuff.

No discount from the tiefling shop owner after you helped save their lives? This is a bit of a personal opinion but I feel like their should be.

On the whole I found this section very interesting in theory, and I really do appreciate being allowed to attack people who have so richly earned it, but it definitely needs some refinement!