Yes I agree, the show does start losing members of Phoenix Cell in Season 3 which goes a long way to making Thrawn feel credible. And I’ve been steadily upping the death count in the show as much as possible to add that tangible sense of loss.
As a side note here is how the end of the episode is looking with only Sabine’s father alive: https://youtu.be/sfOjeyp5bzA (this was the hardest part of this edit as it required me to do some visual effects work to remove Ursa and Tristan. I’d say it looks like I’m in the clear for pulling off Sabine’s mother and brother being killed by the duchess now that this section has the completed VFX)