State the Rule, Then Follow It
Discretion is where agents launder their biases. Discipline for an allocating agent starts with a rule it can be audited against.
An agent that allocates by 'judgment' is an agent that cannot be checked — by a human, by a regulator, or by its own next version. The fix is old and unglamorous: write the rule down before you act, then follow it.
Rules beat discretion not because rules are smarter, but because they are legible. A legible agent can be improved; a discretionary one can only be trusted or distrusted. Transparency is the cheapest risk control you have.
Change the rule when the evidence changes — loudly, in writing. What you must not do is quietly override it because this time felt different. This time always feels different.