Okay, I just finished reading the book in the original Korean edition. I haven’t read the English edition, but it seems that the translation was rendered rather strictly. As @JimInBC quoted above, the book is basically a compilation of short articles published serially in a Korean Buddhist Journal. Thus, it has some inherent structural features. First of all, Every chapter has been set to be quite short and streamlined for the journal format. This links to the extensive quotations of Commentaries and Visuddhimagga since there is not enough space for various interpretations other than the so-called “orthodox” one. Second, the readers of the journal suppose to be Korean Buddhists who are interested in Early Buddhism. Thus, one can easily find brief comparisons of phrases in the Pali canon between Mahayana/Zen literature. There also exist some specific pointers to help East Asian Buddhists, like the Chinese translated terms of choice by Kumarajiva, An Shi Gao, and Xuanzang.
After a brief introduction to the EBT, the chapters are presented in the order of 5 Khandha, 12 Ayatana, 18 dhātu, 22 Indriya, the 4 Noble Truths, the dependent arising, 37 Bodhipakkhiyā dhammā, Samatha and Vipassana, Tisso sikkha, 4 ariya and 10 fetters, samsara and rebirth, and an appendix containing Theravadin Abhidhamma tables like 82 possible dhammas.
It seems that the order is, of course, carefully selected by the Ven. himself. In the introduction, Ven. Kakmuk explicitly states that the key feature of Early Buddhism is “view by dissolution”, or vibhajja, which gives it novelty esp. compared to the Mahayana teaching. It is clear that his extensive quotation and affirmation of Abhidhamma is an extension of the key feature. Cleary there exist a few discords, where he stresses the importance of contemplating khana, insists the translation of “sankhara” in the 5 Khandha must be mental formations (cetasika dhamma) not volition as in DO, the bombardment of Abhidhamma in Samatha-Vipassana section, and so on. Nonetheless, he renders quite strict references, so for the most part, it is easy to find out whether a certain part is from EBT or not. It is a nice introductory 101 material to the EBT guided primarily by the orthodox Theravadin view, especially if you are one of the modern East Asian Mahayana readers. However, if you are not one of them, you might find some inadequacy nonetheless.