It seems far too hypothetical my friend.
Well, perhaps, but it seems ChNN has students who aren't Buddhists.
For instance, since really we are discussing DC and ChNN's views here, -let's just say that someone who had a strong devotion to a certain gyalpo came to study Dzogchen in the DC. They participate in a retreat directly or via webcast. ChNN gives transmission of Guru Yoga, but also the lung for the tuns and the ganapujas as he always does. Guru Drakpur practice is part of those. So said new disciple naturally wants to know more about this very wrathful, intense, knife-legged being they are self-visualizing. I mean, who wouldn't? They get the book on Guru Drakpur. They read about the 8 classes and the very intense provocations and problems ChNN describes with gyalpos. If ChNN truly intended to teach a Dzogchen without Buddhism, he would not be continuously teaching Buddhism, and publishing and distributing Buddhist ideas about the 8 classes etc. Now, this exposure seems much more likely then someone just doing all these things without looking into them, or getting all these transmissions, but just doing Guru Yoga of White Ah along and not exploring what the rest of it is about. It is just quite too hypothetical, not a practical reality. It is an empty example, imho.
ChNN is describing a class of beings using Buddhist terminology. There are other religions who describe these same spirits with their vocabulary.
Let me give you an example. Right now I'll give you a teaching in Portuguese
: "Quando estiveres na reserva, tem cuidado para não te aproximares dos leões
porque te podem atacar".
What I said is "When you're in the game reserve, be carefull so that you don't get close to the lions
because they can attack you".
So, I described the same idea in two different languages. Lion and leão point the same reality in different languages. Calling it gyalpo or orixá (I'm not saying they are the same, because I don't know) is irrelevant. So what Namkhai Norbu is teaching could be taught by any religion that knows what gyalpos are, not mattering the name. Other Buddhists may even not recognize the existence of gyalpos, I don't know. So the eight classes are descriptions of realities. It's not just a Buddhist thing. I'm sure you'll see the same or a similar classification in Hinduism. Perhaps others call them angels, demons, spirits of nature and what have you. Like in Biology, you can find different classifications for the same beings.
Now, let's assume this student doesn't even believe there are such spirits. It doesn't matter. He doesn't need that belief to recognize his natural state. He doesn't need that belief to be present. He doesn't need that belief to integrate his experience. If later he discovers that these beings exist, the name religions give them makes little difference.
Anyway, saying that they will slowly convert to a Buddhist way of thinking through practicing and then giving up their old beliefs is much different then saying they can practice and keep their old beliefs and still go through all the stages of realization at the same time-- which was explicit or implicit in other posts in this forum in the last few weeks. I am glad we are beginning to hone in on what people are actually trying to say or claim.
If Buddhists are correct about their insights regarding reality, it's natural that the more one practices the more one gets closer to what Buddhists say about some things. But now we are talking about the fruit, not the path. And this seems a source of confusion. Sadharma and Buddhadharma are not the same. What you seem to be saying is that Sadharma is only possible via Buddhism. Well, this is what Buddhists think. I think Sadharma is possible via Dzogchen, without Buddhism. One could argue that it is even possible without Buddhadharma, if we limit the concept of Buddhadharma to the Dharma taught by Buddha and not all correct teachings that lead to enlightenment. We end up entangled in concepts, no matter what.