I do have direct knowledge as to the legal field. The credentialing test bears virtually no resemblance to the practice of law.
Law varies from jurisdiction to jurisdiction and 80% of the licensing exam in virtually every state is based on made-up law, which is invalid in every single state, and invalid under federal law. You have to memorize completely irrelevant law and apply it to pass the exam. Of that 80%, 50% is multiple choice. There is never a circumstance in which you practice law by multiple choice, applying memorized nonsense law.
20% of the exam is based on law you are given during the exam. It is also made-up law, but if you go to a new jurisdiction to practice law (or the law changes), you do have to be able to interpret the new law in the same way you are required to on the exam. It would literally be malpractice, however, to do so in 90 minutes, without being able to associate in someone familiar with the law, and without being able to review additional case law.
I guided approximately 1800 individuals who graduated after completing 3 years of study in the law through the bar exam. As did everyone I know with similar job responsibilities, I taught them how to beat the exam - how to reverse engineer the law from the fact patterns, how to "analyze" a fact pattern by copying the law and inserting facts in place of legal terms, how to eliminate trick answers in the multiple choice, etc. The ones who were most successful were skilled test takers - and those who could write confidently even though they knew very little. A number of students are the top of each class failed each year because they couldn't force their brains to dumb the law down enough to pass.
Dentistry and piloting credentialing may be better matched to the profession - as I said - I have no experience in licensing those professions. But I am confident I could teach any reasonably intelligent motivated person to pass the bar, without ever taking a single law school class.
And if you don't want a lawyer who hasn't passed the bar exam, make sure you don't hire an attorney who graduated from a Wisconsin law school . . . They are automatically licensed in Wisconsin, and after practicing for a few years can transfer their license to most states.