Mindlessly following orders is your duty as a soldier, it has nothing to do with them being robotic psycopaths or not.
Maybe fewer of them are frothing at the mouth to harm civilians the way cops are, I have no idea, but assuming an army is just not going to follow orders because you think they're "normal people" is a risky and stupid position to take.
Whenever you mean it sincerely is a good time to say it