I'm sure my view was at least partially colored by the inevitable comparison to the overall quality of "Andor", but even trying my best to separate that, I was definitely underwhelmed with "Tales of the Underworld". They were fine, but neither were particularly exciting or felt very inspired. These two arcs were easily my least favorite of all the "Tales" shows so far. I too, missed the context of Assaj dying in a novel and was a little confused. I don't think my issues were necessarily with the character selection, I did like the choices initially, but rather like Jeff said, I just found the writing to be far too formulaic.
My wife and I both were nodding off too, not something that I ever do during SW, especially during 15-minute shorts...