I love your thoughts on this. As someone who has studied educational design and psychology, I’d like to offer a perspective on what you’re describing.
In educational psychology, there are three categories of educational goals: knowledge, skills, and attitudes. (Presently, there is a bias against teaching attitudes, so the “KSA” is frequently changed to “knowledge, skills, and abilities,” which is incorrect and redundant.)
It seems that your “What” book represents the knowledge of the field, the “How” the skills, and the “Why” the attitude.
I think you would be interested in reading about Bloom’s taxonomy of educational objectives. I think it would integrate well with the model you are creating, especially in light of the comments earlier about what “depth” means in this context and whether “What” or “How” is of greater depth. Either one can be shallow or deep as they relate to different kinds of learning.
Buddhism: What: What Makes You Not a Buddhist by Dzongsar Jamyang Khyentse Rinpoche (There are probably books with more detail and a more broad view, but I love this one for how it contrasts ideas from popular culture with Buddhism to highlight similarities and differences, making it very accessible); How: Meditation Is Not What You Think by Jon Kabat-Zinn; Why: Bring Me the Rhinoceros by John Tarrant (It’s not explicit in explaining the why, but presents zen koans that cause you to enter the mindset of letting go of assumptions)
Crisis Intervention Counseling: What: Interviewing for Solutions by Insoo Kim Berg and Peter De Jong; How: Motivational Interviewing by Miller and Rollnick; Why: On Living by Kerry Egan
Teaching: What: Understanding by Design; How: Made to Stick by Dan and Chip Heath (not strictly a “How” book, but an excellent book to develop strategy for presenting curriculum); Why: Pedagogy of the Oppressed by Paulo Freire
I don’t want your money—as soon as I finished this article I started thinking about the topics that I study the most and what books I would recommend to people. Also, I am a suicide intervention trainer by trade, so I have an obsession with figuring out how to teach people about empathy. :D