I never pick up a book about nutrition or fitness and see it as THE health Bible. I see them more as individual books within the larger health scripture. Intelligent Fitness is a good addition to the field and having done a few 5-2 workouts (the prescribed method in the book) I do feel like I'm pushing myself and living a healthier life. The 5-2 method keeps things interesting, but I do feel like I have to incorporate knowledge from other sources (more on them in a moment).
I liked the stories about behind the scenes of training actors and actresses and the fact that there are workouts for women is a nice change of pace because most fitness books lack the angles of what works for men and what works for women. Simon has a great attitude towards health and exercise that makes you want to exercise not out of necessity but out of fun.
Some pointers:
For the 2 minutes of cardio in between sets, I googled examples. Obviously, if you have access to a treadmill or stationary bike, those are great options. If you don't, like the book says, don't let machines get in the way. I do two minutes of a mix between jumping jacks, mountain climbers, or high knees.
The workout examples in the book are more full body routines. I looked to established trainers to develop more targeted (legs, upper body) workouts like Jeff Cavaliere at AthleanX and then just plugged in the exercises into the 5-2 structure.
In regards to nutrition, I recommend The Wild Diet by Abel James and Fit Men Cook by Kevin Curry. They have some great perspectives on other fitness aspects like fasting and meals without the blandness of most diets.
Hope this helps! Health requires discipline, but it is all worth it!