Yes, Prof. Zuntz is painfully aware of this fact (cf. his articles, specially his On Greek Primers and Griechischer Anfängerunterricht - Gestern, heute und morgen). His “solution” was at the beginning to group those phrases in subjects and to add an anthology (the gradation itself is well done). Take a look at his method and read his Vorwort and judge for yourself if he accomplished what he intended.
I do honestly believe that his method is the best but not the pedagogical ideal (mainly because of this reason), which is why (as I said in the review and elsewhere) I always use his method in combination with a graded reader. And we must also remember he lived in a time where an elite group of people (to which Prof. Zuntz belonged) got an unimaginable amount of classical knowledge at home and very early in school, so its not surprising that he supposed that any teacher (or parent) would be knowledgeable enough to first introduce the learner to the context of the fragments and explain their importance so that they made sense and aroused the interest of an already advanced school boy. (Understanding this privileged position of the greatest scholars of the past century is something that some teachers or scholars today fail to do and end up making impossible demands to a new and totally different generation of students).
Again, Zuntz himself in his articles answers this precise question better than anyone else, and like I said, his arguments are compelling. We also have to understand that he lived in a time where the good materials I’ve mentioned were virtually unknown, extremely new or not yet existent, which is why he pronounced his judgements based on his observations of the material he had at hand, which is very, very bad, disastrous and honestly depressing (cf. Zuntz’s On First Looking into Chase and Phillips: Notes on the Teaching of Beginners’ Greek and Linguistics and the Teaching of Greek). So I can understand why he looked with suspicion those methods that resembled the useless ramble that he knew.
I don’t disagree, and I confess that I’m quite fond of the Reading Greek, like I said its holistic approach makes it very attractive (the answers sheet alone must be a heavenly deliverance to self-taught learners), the Independent Study Guide or the The World of Athens are irreplaceable enticements to the curiosity of the pupils.
But if push came to pull I’d stick with Athenaze because the JACT is not “ørbergian” enough, proof of this is that I’ve encountered pupils and teachers who, having such an excellent reader fall on trap of focusing more on the English explanations and the technicalities of the grammar notes rather than on the excellent text itself. Or even worse, they end up doing this whole torture of morphological analysis and translation into English which kills the whole purpose of a graded reader. (Again, read Prof. Thomson’s article)
Maybe I’m wrong but I get the feeling that (not only here) there’s an “English language bias” were a lot of excellent material is ignored at best or “discriminated” at worse simply because it’s written in a language other than English.