The grapevine is the most important source of accurate information. It's the collected wisdom of people who know how the system works and what it will and won't tolerate. My experience has been that about three years of post-college experience are necessary to validate and firmly implant this lesson. Students realize almost immediately that secretaries, mail room people, librarians, assistant everybodies, and building and grounds work to know what is going on, and they find it out first. Support people understand that information is vital to success on the job and a source of power.
Career counselors have a duty never to demean the importance of staying plugged in to the grapevine.
Not that every student will get it when you explain, but offering the explanation is important. Rank is not as important as influence. Students know something about the differences. For example, it's a rare, and remarkably dim, student who doesn't know that the Dean's secretary, not the Dean, is most important in getting into closed classes, obtaining a rule variation, even in advising on the best time and approach to get the Dean to grant a special request. That's an important principle in the real world where secretaries often have as much, if not more, power than their counterparts did on campus and must be worked with and through.