I think you have an incorrect paradigm into which you would like to fit what you think the Bible describes. I also think that your knowledge of the ancient world is less than perfect.
There, I was nice.
Your conclusion misses a third, and much more logical conclusion, all these closely intertwined cultures simply share stories and archetypes. They may in no way be related on the deep level you imply but these are just cultural archetypes common to the region. The Israelite people and their ancestors were one of oldest intact groups in the area. Following their history, they have been part of all the main cultures in the region. They were also a culture that prized literacy and so their stories were carried forward by all people in their culture so when a group immigrated to an area or were conquered, their stories followed them and over time, became part of that culture too.
You can see similar cultural archetypes if you look at the various cultures of ancient Europe, Asia, and the Americas. They have archetypes that carry forward across the various cultures of their region most likely due to groups intermingling in some sort of fashion, and sharing the stories.
So far as I understand it, Osiris was cut into 14 pieces, but the mother goddess couldn’t find the 14th piece (his willy), so she formed one and stuck it on. Horus was then conceived, which maybe the heathens consider the Resurrection of Osiris. He (Osiris) didn’t rise again, but rather was zombified and went off to dwell in the underworld. Horus, however, is never said to have died and risen again. They are also wrong about him being called “the son of God” and other things. There is no evidence for these claims, or they occur after the time of Christ. Even his birth date, which they sometimes mention, isn’t even in December. It’s in October, or November.
These are simply the inventions of heathens making claims with no historical evidence.
One other point that is missed is that the Torah/Bible describe the Horites as being a people who were driven out of the land before Abraham’s descendents arrived- not part of Abraham’s descendents.
Another dose of speculative mishmash.
the Bible doesn’t say anything about the Horites having castes or about them controlling the trade routes from north Africa to India. There were two or more trade routes and they didn’t necessarily pass through Canaan