I can respect this outlook. Those are good points I hadn't considered. It is true most paladins would consider collateral damage to be avoided, and with the circumstances akin to self preservation and recent traumatic events pushing for peaceful resolution or even fear I can understand the reactions taken somewhat. One thing I wanted to point out that does help support a bit of my stance:
Azrael has tenets. Two of which I'd say do not outright counter your suggestion, but would at the least support why I'm thinking as I am currently. The By Any Means Necessary tenet would suggest that collateral damage is not generally on the forefront of a vengeance paladin's mind. Now this monk that hit him wasn't a Mara, no, but an enemy no doubt, as she did attack him with lethal damage, and represented a corrupt group. This of course doesn't mean collateral damage is never thought about, only that it's likely not something often kept in mind to overshadow justice or revenge. The Restitution tenet suggests also that Azrael might care more about how this group is affecting the populace than things like property damage or more centralized notions like self preservation or fear (paladin->fear). Not that I think he needs it, but I'm sure if @DansGaming ever wants inspiration for what he thinks his character would do, the tenets he follows would be great reference.
In regards to the barbarian, that point makes an excellent amount of sense, as even in an episode where the barbarian and the rogue went off and swindled some dwarves, Max did state that his character more or less fell in line at one point with old habits from when he was a slave. This is a tendency I can now see. Perhaps I assumed that was the source of his rage and because of that, it would make more sense to lash out when treated as such as seen in an accounts of former slaves, but then again I should not assume.
Thank you for the perspective.