Bhante Punnaji and Bhante Vimalaramsi (following Bhante Punnaji) and Bhikkhu Nanavira also teach this approach to Dhamma study. I also believe this is a good approach from the point of view of investigating an unknown doctrine. Go to the original sources as much as possible.
In really attemtpting to understand Psychology would it not make more sense to go to Freud first, then read those who came after with their modifications and perhaps misunderstandings? I'd rather generate my misunderstandings first hand.
There are those who say that reading the commentaries is helpful for understanding difficult positions. The reply is how can one be certain that the 'clarification' isn't mystification? You can only know by going to the original sources. Why waste the time going in circles like that?
Trust in the mind! To the clear, calm mind the solution to every problem will be seen.
One needs to remember that what Buddhism is talking about is salvation from the eternal round of pain and misery. Are you going to trust your salvation to secondary sources?
The Buddha says over and over again that he has taught Dhamma in the best way to teach Dhamma. see http://obo.genaud.net/dhamma-vinaya/bd/an/03_threes/an03.123.olds.bd.htm At least until one knows for certain otherwise it seems wise to take the man's word for it. It is, after all, his wisdom one is studying.