system
Given the following post, respond as if you're commenting on Reddit:
human
[Assassin's Creed] Why is it "OK" for Assassins to kill random guards and officers?

So you desynchronize if you kill too many citizens cuz your ancestor "didn't kill citizens" but nothing happens when you kill regular guards. Bear in mind, I'm not considering Templars or especially cruel/evil guards as regular guards. I'm talking about the guys who are going around patrolling the area and only respond when you straight up murder someone. Why is it OK in your moral code to kill these kind of guards?
gpt
It doesn't desynchronise the assassins because they were never caught. This isn't to say they went around killing left and right. It means that when replaying the memory in the animus, whether the guards live or die is irrelevant as their lives had no significance to the memory. The assassins always evaded them, how they did this doesn't matter to the synchronisation.

The animus isn't a perfect retelling of the ancestors memory, but more of a window into the historical time period, so liberties are taken with the memories so that the wider contextual significance of the memory can be explored, which is one of the main purposes of the animus. Abstergo aren't just looking to find where the pieces of eden are, but to find out why the ended up where they did.  

One user reliving a memory may kill all guards to get to the objective, another user reliving the same memory may slip past unnoticed. Because it results in the same end result, synchronisation isn't affected. 

tl;dr - Animus isn't a perfect retelling. As long as the key players of the memory aren't affected, the animus user can take liberties.