For Minthara I'm just roleplaying as the Durge who couldn't control themselves and led Minthara to the grove. They feel incredibly shit about it as they thought they were able to control themselves after killing Alfira, but the urge to slaughter was too strong. Afterwards they seek comfort in Minthara, probably another monster such as themselves. This is incredibly dumb on my part, but I have no other idea how to justify getting Minthara as a romance and getting the good ending.
If I didn't have to slaughter/ignore the grove I'd pick Minthara over Halsin every single time.
It's also hard to logically justify recruiting Minthara.
The basic premise there is to save yourself by infiltrating the Cult of the Absolute to find their secret stash of cure-tadpole.
(Lae'zel's creche has arguably* better chances.)
If I'm going to non-stupidly recruit Minthara without being a sociopath, I'd exhaust grove options, exhaust Halsin option and possibly Gut/Hag - then sacrifice the grove out of desperation. Heck, a sympathetic MC might even try forcing Zevlor to leave before the attack.
*
A learned MC can probably deduce the zhaith'sk is a front for docile self-extermination.
