Ohhhhh I see. That’s really unfortunate actually. To be honest the the writer of this book probably did not have a very strong understanding of kanji, otherwise he probably wouldnt have compiled it like that.
The reason I say this is that the position of a radical plays a vital role in the meaning the kanji has, and also is probably the biggest thing that trips people up in terms of reading the wrong thing accidentally. For example. 奪、奮、These share exactly the same shape and pattern (crown component), and are something people are likely to mistake. Yet for some reason he didn’t even mention the second one (despite it being the most similar!).
Putting the same component on the left, or the right, or even the bottom changes the meaning quite a bit, as well as not being as important in regard to accidentally mistaking similar ones.
Edit - I do like that it says which kanji have the same sound though… Although the same sound in kunyomi is far more important than onyomi. So hopefully it does both.
2nd edit - Sorry, I didn’t make this very clear. Think of it this way. He shows the structure, and that is great. He also shows kanji that have that shape, which is great. (He also shows a lot of others that don’t have that shape at all which is a bit strange). But the most important thing that he is missing is the kanji that actually share the same radical in the same position. This is extremely important, as it plays a role in the nuance and meaning, and recognition of the kanji.
For example imagine if someone was teaching English, and they were teaching un-. Unprofessional, uneducated, undivided, uncool. (Great, meaning stays the same)
Then suddenly they start saying fun, bun, lung, sung. (still has un in the words, meaning is wildly different however). It’s a bit like this.