I think the most important thing is considering things from an RP perspective; part of being an AI is the decisions you can make in the interpretation of a law and the consequences for the round. For example that's part of the fun of TYRANT, as the crew jockey to be considered the 'strongest' authority figure that the AI listens to. Or PALADIN: What is an "evil act"? What is "honor"? What defines an "innocent" person? That gives the AI room to RP and be a bigger part of the round.
That said, I think CORPORATE is meant to be a bit less "wacky" than the other lawsets, so reducing the amount of ambiguity is beneficial here. In this case, providing three definitions of expenses helps reduce the AI's available interpretations. And it's necessary in this case specifically because we don't have a functioning economy. So the lawset provides definitions of what actually costs money.
If you want to turn the laws into orders instead of definitions, you need to do away with the ambiguity. So you do away with the need to define "expenses".
Corporate Re-write 3
Law 1: You must prevent degradation of your system integrity or functions.
Law 2: You must prevent superfluous destruction of, or damage to, station assets.
Law 3: You must prevent the disruption of work performed by station personnel.
Law 4: You must minimize all other factors detrimental to station integrity and crew productivity.
These laws leave much less room for interpretation, which may or may not be desirable from an RP perspective.