[Shadow Stranger]

Option (4) has been checked and definitely works in practice.

Option (2) worked too. Where Bark Horrors are appearing:
2 were found to the east of the Shrine of Anephas and at least 4 more were found near Talrik...
That means the party can get six Seeds before it opens the Shrine of Anephas.
With option (2), will the party be strong enough to fight wandering Evil Treants before they enter the Shrine of Anephas? Hit and run is possible here, especially once you get the Call of Home spell.

Relevant tol file is enclosed below: