The AKHG was mevatel the yetzer hara for avoda zara.
Later they tried to be mevatel the yetzer hara for aroyos. However it is mashma from these Gemaras 63/64 that the yetzer hara for az only arrived through aroyos. So why would the process be for removing yetzer hara for a"z alone as if it was an independent thing. According to these Gemaras it evolved from something else?
joe, ny ny
The Gemara merely implies that one will do Avodah Zarah in order to get to Arayos. This does not mean that the source of the two Yetzer Haras are the same, but rather that the desire for Arayos will make one do other sins in order to be able to do the Arayos. However, as logic would dictate, the two can be totally unrelated. Not everyone who wants to do Avodah Zarah wants to do Arayos, and not everyone who wants to do Arayos wants to do Avodah Zarah. It is therefore clear that these are two different evil inclinations.
All the best,
Yaakov Montrose