We never have enough information to know what goes on in Starfleet ships. That's not a particularly insightful post. If we were limited to just what was known through exposition, there'd be nothing worth discussing anymore. Most of these threads are all rehashing topics that are decades old. So we extrapolate from what little is known. And Spock thought Khan could change the prefix code. Does that mean it's really hard or really easy? Either conclusion is possible, and neither are foolish if the arguments are sound.