They may be different now. I pray that they are. But when I went to high school, the guidance counselors were notoriously bad. I hope that my school was an exception and that most students got solid and practical advice from their guidance departments.
When I mentioned my plans to go to law school, I was told to study Latin because the law has many Latin phrases. I ignored that and studied French which was about as handy. I suspect that classmates who studied German or Spanish got along just fine.
I was also advised to major in political science as an undergraduate. I found that to be another myth; in fact, an English major may be one of the best choices for future law students due to its emphasis on the ability to write. I knew students with degrees in agriculture and drama, however, who experienced no extra burden in studying the law.
All of which makes me wonder how many of the common career tips are completely off the mark.