I would suggest not reading too much in these self-help books. NYT, WSJ etc have great "relationship" with high-end publishers who propel several poorly researched myths but written in very appealing way. Self-help books are amazing amazing business netting 10s of millions of dollars in book sells per book. These publishers also know what sells: bottle a simple advise that is rather naive but has lots of anecdots and make claims to have found magic formula to make anyone insanely successful at everything. Entire self-help industry is disgusting because they take advantage of human vulnerability to the maximum extent with full knowledge of what they are doing. To some, it serves purpose of getting inspired for a week or month for $20 and that's their best outcome.

The main topic discussed in this book, i.e. breadth vs depth is perenial delima also recasted in multiple forms such as exploitation vs exploration. There is no magic bullet in one side or another. The art of getting somewhere is very delicate balance between two. The best approach that has worked for people is either get lucky or find people who have made mistakes, analyze their mistake and, of course, get little bit less lucky.