[OrangeGuutan]

"I believe that apprentices could start practicing medicine and law much earlier in their careers and learn the facts they need along the way."

As a medical student that just today finished his first year, I take a little offense to that ;) Namely, there are already fields for exactly what you describe: nurse practitioners, and to a lesser extent, physician assistants. They are taught general patterns of a small set of diseases, and can only diagnose that small set of diseases that specifically follow the course (i.e., pattern) that they were taught.

After a year of schooling, I am nowhere near ready to practice internal medicine or family medicine, let alone specialty fields. I can spot your garden variety shingles, ear infection, etc., but anything more requires experience - and knowledge - that I do not yet possess (even after a year of grueling studying!).