Finally, the quote is not specific . . . are you talking about a single galaxy's practice? Wolf behaviors in a campaign? what happened in the battle for a contested world? I can think of a few instances where that sentence might have applied, by itself it means little and is just cherry-picked . . . what is the context of the single sentence?
Your lengthy bit about morality being “we were terrible before, so it’s fine to be terrible forever” is… awkward. But my comment about the ares convention was off hand and not much of an effort. So yeah, doesn’t apply here.
As for the part I quoted. More at length:
“The two primary Wolf Empire thrusts targeted Denebola and Castor. On Denebola, rumors of Alaric Ward’s presence among the Clan Wolf warriors proved true this time. Alaric’s Silver Keshik led the Ninth Wolf Guard Striker and Seventy-ninth Wolf Battle Clusters into battle against the Fifteenth Principes Guards. Since the Wolves arrived at a pirate point, the Fifteenth’s conventional assets had little time to properly dig in along the lone approach to St. Cameron, so the RAF defenders were forced to fight on the move or risk being scattered. Alaric cast his net wide and surrounded the Fifteenth and its support elements. As he marched toward St. Cameron, his Wolves systematically destroyed the disorganized defenders. Depending on which Cluster or Trinary commander was on the scene, those RAF soldiers who surrendered were absorbed into the Wolf Empire’s touman, assimilated into the civilian castes, or executed.“
- Shattered Fortress, pg85
Wolf forces under Alaric’s command, shortly after the wall retracted. Shattered fortress is kind of all over the map on how wolves treat defeated units. Which, not a homogenous culture, so that make sense.
But the only times that wolves went out of their way to slaughter defeated troops appear to be when Alaric is directly in command. There’s a different planet, Alula Australis, where forces under his command slaughtered defenders functionally without quarter. It paints a picture where Alaric has what might be good plans and orders, but he’s unable to keep a clear head when he’s directly involved.