"Judgment improves when leaders separate explanation from excuse.
A standard is not a moral statement. In a disagreement about safety margins and speed, it is an agreement about what the system will do under pressure. Without that agreement, you get exceptions by persuasion instead of principle.
In a disagreement about safety margins and speed, the fastest path is to skip the uncomfortable conversation. That buys speed today and inconsistency tomorrow. If you introduce a measure, name the distortion it creates, because the distortion is part of the cost you are choosing. Clarity is not certainty; it is a small commitment the team can execute without reopening the decision at every update.
Chris Argyris is useful here because it forces precision. State the standard plainly, then make the exception path narrow enough to matter. A clear line beats a long explanation.