Huh. I had no idea that was possible. They did spawn for me when ignoring the boy and stepping into the water once, I think? Triggers combat for that character.
Maybe you can sacrifice one and have the others sneak up on the harpies?
they detect me always after the cutscene, and i'm playing solo
Drinking invisibility potion and running away? If they don't despawn, they should still be there. Unless, you're also worried about the song's instant chance to hypnotize as soon as combat begins. I really don't know what to do about that
Maybe, you could also have Shovel walk into the water in place of a companion? That might start combat right here and there
