Captain Cook wasn't a member of Starfleet. As for Project Genesis, it wasn't Marcus' place to tell Starfleet officers how to do their jobs.
It was their job to find a test site that was acceptable to Marcus. Period, full stop.
Oh, and Starfleet has
no standards or regulations to govern Kirk's behavior, because Starfleet is fictitious - it exists to support the characters in their motivations and back stories, not to inhibit their behavior where that hurts the drama.