User blog comment:Master Sima Yi/Assassinews 03-03-'13 — Assassin's Creed IV: Black Flag trailer and screenshots/@comment-4829046-20130307034904/@comment-4636255-20130307124743

I know, but that doesn't mean Ubi can't make one Assassin with a strong moral compass. Besides each Assassin was benevolent (up to a point).

The only guards Altaïr canonically killed were the 60 Templar knights, guards who were raping or harassing, and the guards who helped his targets. All other deaths were avoidable.

Ezio killed guards more ruthlessly, but most of them were Templars or mercenaries whose deaths were necessary.

Connor killed guards the same way Altaïr did.

Like I said, most of them do care bout guards, and it's the players temperament that affects it.