Sira was almost unknown NPC who was only given prominence for that story arc, and Delaryn was literally created for it. Saying it sucks to become attached to them just for them to die is missing the point of the story: you’re supposed to feel bad about their fates, so that it adds emotional weight to the proceedings. But not too much weight, because they are just redshirts.
Characters dying in stories, movies, etc. is supposed to make you feel something.
My problem with their fates is not that they die, it’s that it is handled in such a predictable way. Kind of like Kindy in The Shattering. “Will meet a terrible fate that she doesn’t deserve” was basically tattooed on her forehead from the start, which to me, meant that her fate meant very little. Same with Sira and Delaryn, or Lorash Sunbeam. They represent cowardly writing choices - if you really want us to care, kill off someone who matters.
Their deaths reek of cheap manipulation. It should have been Maieve and Shandris. Instead of Lorash, kill off Halduron. Then someone might actually feel something.