That last formula is the way I would suggest we try to deal with it.
On the one hand, it makes no sense to say this figure is set in cement and you can never depart from it under any circumstances. On the other hand, you obviously don't want a system in which it's, “Oh well, that's just a rule.” What you want is reasonable latitude for people to take account of circumstances, to exercise judgment, and if they break a rule, ask them why. If they have a fairly good reason, I'll go along with that. Accept that a lot of different circumstances can arise in a government where deputies and assistant deputies, or whomever, need to make judgment calls. In terms of how government looks to the public, instead of being rigidly bureaucratic, the ability to do sensible things in situations is really quite important for the reputation not of a particular government but of government as an institution.