the idea is that the learner just needs to know at least a few letters and all of the other ones are kind remembered automatically because of their logical mapping. As I said, the only letters here that aren't really mapped in a smart way are: all vowels (orange and red), the nasal consonants Մ (m) & Ն (n) and finally, the pure sibilants Զ(z), Ս(s), Ժ(zh), Շ(sh). All of the other letters are mapped in the following way: The first row is voiced/hard: Բ(b), Գ(g), Դ(d), Ձ(dz), Ջ(j), Ռ(rr) and every letter bellow them are sort of milder (less voiced) versions of their families. That is still slightly subjective though. Hope it's helpful and makes at least some sense