It's to do with picking, if you haven't picked anything then it will apply it to the instance with the lowest UID. In this example you pick twice, for each goblin so all of them, then goblin state = aware, so any goblin that is aware, then the condition is applied only to those picked. It narrows it down as you are imagining, when you run that conditions of goblin.x > player.x it is choosing and applying it to the goblins that were picked i.e. all goblins that are 'aware'. Also if you were to run the action on those meeting the condition it will again pick the same goblin instances that were picked, those that are in 'aware' state.
So I just tested my new code, and only one goblin is turning, despite both being "alert" in the instance variables. Does this mean it's only picking one instance, shouldn't the "For Each" at the top of this event flow be covering this?
p.s. > Oh and the other question, yes mirroring the object will mirror the LOS so it is facing the other way for detection.
Thank you so much, some old forum posts confused me on this when it was not a feature at the time.