My brother in law is a consultant - oncologist at a major hospital. Having stayed with him for a number of years while he was a student, I'd like to disagree with your statement that it is possible for a person studying medicine to join the top 1% of income earners quickly!!!
Here is a little bit of his story.
Coming from Chinese, Malaysian background, my brother in law's parents (ie my in laws) have sacrificed so much for him to study medicine. There was a period of time whilst I was working in Malaysia with my wife and we both stayed with my in laws. The stress they went through exchanging RM (Malaysian Ringgit) to AUD (Australian Dollars) to pay for his fees was incredible. Every day they watched the exchange rate and a minor change with the AUD becoming higher by a few cents was a major event.
Each year they faithfully paid his fees which were equivalent to what my father in law was earning in Malaysia at that time.
My wife and I then moved back to Australia and lived with my brother in law while he was studying. Studying until 3 am was not uncommon for my brother in law. In his first years of working he worked in an appalling hospital which shall remain nameless. 16 hr shifts were common. Any thoughts about money were completely irrelevant to him. He came home, went to sleep and then woke up to go to work again - repeating the whole 16 hour experience over and over again.
The exams and study required for him to reach consultant status were incredibly difficult and draining. He was studying at the same time as he was working.
He is now 39 and a consultant. He begins work at about 8.00 am and works well into the evening after he returns from the hospital at 6.30pm.
It has taken him the best part of 20 years to reach this level and his income is no where near 7 figures!!!
Money is not my brother in law's aim. He is a kind person and wants to help people. His job takes its toll on him and when his patients pass away he does it tough.
He will marry next year - no doubt his studies have also made it difficult for him to meet a spouse and have a family of his own......
His circumstances are a little different and atypical. But you are pretty spot on in your observations.
Firstly as an overseas student, he would have found it a little harder to ascend the ladder to becoming a consultant. Many medical graduates have reached consultant status by age 30. You graduate from medical school aged 23 and if you ascend smoothly through the ranks, you will be a specialist in any field by 30.
Secondly, the speciality he has chosen is one of the lowest earning of all the specialities. So he is unlikely to be part of the 1% of income earners within medicine, ever.
Thirdly, as a purely hospital employed specialist, his earning potential is capped. Essentially, he is a government employee and his total package only comes to about 300k which means he gets to take home about 150k per year or less. However, it is not all about money and he must have chosen his field due to professional interest.
For maximal earning potential within medicine, I would advise the ROAD specialities. (R) radiology, (o) orthopaedics, opthalmology, (A)anesthetics and (D) dermatology. If these don't appeal consider plastic surgery and obstetrics/gynecology.