I’m currently in an EMT course, and we’ve discussed the differences between ambulance jockeys and ER techs. EMTs in the field operate largely on what are called ‘Off-line orders’- the standing commands in place that guide an EMT’s decisions and courses of actions when certain criteria are met. They can call for ‘online orders’ when they need additional guidance, as field conditions are sometimes not what was expected or are handled by the offline orders. ER Techs on the other hand, wait for orders. A doctor gives an order, then it is followed, generally no more and definitely no less.

It is worth noting that EMTs, if given an order that is contraindicated or outside their scope of practice(what they’re legally allowed to do), are supposed to ask for clarification/a reason for the order, as its possible perhaps the doctor on the phone misunderstood, or knows something the EMT does not. (Ultimately they are not to do more harm, and can decline orders they are uncomfortable with or cannot legally do, but they had better have a reason for it.)

The Ephoroi operate outside the palace, away from the Emperor, and from the Legio. They have their goals, and have tremendous latitude in accomplishing that goal. You see it in The Emperor’s Legion when Navradavan decides he’s not just going to collect the Black Ship Sisters- he chooses to stop at every possible hint of a Sister of Silence convent on his way back. It’s implied that wasn’t an explicit order. So Arturia is used to being given a mission and choosing however she needs to accomplish that goal. She contacts Terra when she must, but for most work she can handle it on her own. 

So leading into the question of her being willing to follow a perhaps amoral command, or a command that contradicts the apparent overarching goal and where the headcanon begins. Unlike most in-house Custodes, Ephoroi are used to a certain amount of autonomy, and can and will question if an order does not make sense given field conditions. Ultimately she will follow the order if pushed by the Emperor, but not before attempting to clarify or even requesting additional consult in the form of Arlette or Constantin or Malcador or one of the Tribunate.