Arka survives if you never open the door to the cell. I was surprised to see her when I came back from killing the goblins and just noticed I forgot to go in there. However, the knocked out druid in the cave was dead and the goblins with him were gone…
She was near Kanon’s grave with her brother, the blacksmith, etc.
Ah thanks for pointing that out I edited my post. But is it possible to save Findal with this approach or is it just a swap of the NPCs that will die, so Findal instead of Arka or vice versa depending on the route you take?