If I understand the exercises correctly, the flexibility are not just flexibility exercises, they are exercises to drag the roll-in embouchure into the middle to lower registers, no?
Also, the BE exercises aren't just these two (long tones & flexibility). The tonguing through the teeth are important exercises as are the exercises which drag the roll-out into the upper registers (and the opposite). As I recall, the only exercises that don't have an added BE goal to them are the double and triple tonguing exercises and the cresc, decresc exercises. The others are not merely redundancies to the kinds of exercises that we all play anyway, but they have an added association to some aspect of the BE that needs developing.