But the fact that it reads like a historical narrative does put its creation after the invention of the style of historical narrative.
Which doesn't say much. People tried to record history as far back as the cavemen paintings of battles, some 20,000+ years ago. And in written form, a (half mythical) list of Sumerian kings and where they ruled, over whom, and when, is attested in an inscription as early as 2000 BCE on the Weld-Blundell Prism. The first known Egyptian attempt at keeping a historical list of kings is the Palermo Stone, dated circa 25'th century BCE, i.e., even earlier than the one we have from the Sumerians.
So, yeah, if all you're trying to say is that the Hebrew attempt at keeping history is later than 2000 BCE, we can agree there.
As I say, there is a risk to success. I was talking about the Septuagint stories being backstories for the Yahweh cult nearly two years before I discovered the Ptolemeys had previously successfully created Serapis.
Serapis is actually an awful example for your case there, since it's actually a Greek contraction of Osiris-Apis, a combination of two Egyptian gods. The Egyptians had been gradually merging their gods for 3000 years or so. E.g., Amun-Ra. Also according to Tacitus, it wasn't even really invented by the Ptolemys, it was the local god of the village they expanded into becoming Alexandria.
And even if you want to make Serapis a Greek invention, it was nevertheless a mix of two major Egyptian gods who had had increasingly overlapping domains anyway, and actually more Osiris than Apis. Osiris-Apis mostly kept the Osiris story, including having Isis as a wife and Horus as a kid, and all. And its acceptance by the Egyptians actually is explained by that: they were mostly just asked to keep worshipping their top God (Osiris had crawled back to the top by that time) with a different beard.
That was the other master-stroke, actually. Osiris was the only major male god who didn't have an animal head. So really, all the Greeks did to hellenize him was to give him a Greek beard instead of the traditional Beard Of Power +5, and a more western pose in the statues.
I.e., in any case Serapis doesn't appear out of nowhere, but is really just a slightly upgraded Osiris. As an example of inventing gods out of nowhere, you can't get a much bigger fail than using Serapis.
Speaking of whom I have never come across a single archaeological find of any inscription indicating there were ever any people who were called or who called themselves Canaanites. Arkies have identified the Phoenicians cities by their own names and of course the Hellenes of Joppa but nothing remotely like it for "Canaan." In fact the only usage I have found of that word among arkies (who should know better) is as a generic reference for the region much as I use bibleland.
In other words the Canaanites in addition to the Philistines are another fictional people invented by the Septuagint creators. Of course anyone who is not a believers will produce physical evidence of the ancient usage of the word not a one off find on some inscription which could as easily been where the Septuagint creators found the word.
"Canaanites" is just based on their geographical location, i.e., in Canaan. So it's really like referring to the Texans as Texans.
And references to Canaan by that name exist independent of the OT, and
long before any of that OT stuff was composed anyway.
But to answer the question, try for example the Amarna letters. E.g., the Phoenicians in the area refer to themselves as Kenaani or Kinaani (i.e., Canaanites) in those letters.
Speaking of people who are found only in the Septuagint, Hebrews are among them as are Israelites. Only the name Judea/Judean has actually had people who called themselves that known to real history. Arkies find no such names in bibleland until the Greek period where Judea begins to appear.
Unsurprising, since Judaea is the Latin form of Judah. It may come as a surprise to you, but people do that kind of mangling foreign names to this day. E.g., what you call Rome is called Roma by its inhabitants, and they call their country Italia not Italy. Moskow is actually called Moskva in Russian, and they call their country Rossia, not Russia. Etc.
A lot of this is unlearning because so much has been spoken so commonly and with such authority that it takes a while to realize they are also found only in fiction. And as from Josephus, 'Jews who take their name from their land Judea.'
Whop-de-do, major revelation that

Of course Josephus writing in Latin would use the Latin name.
I have a whole other set of references which point to the consensus among linguists that what is called Hebrew is really Phoenician found where the Septuagint says the Jews lived. Of course believers are still wont to make claims about differences before spelling and grammar were standardized.
Sort of. The whole area spoke various dialects of related semitic languages descendants of Akkadian, of which Phoenician, Hebrew and Aramaic are three. But yes, the languages were closely related.
A more interesting example is from Ugarit with a phonetic version of cuneiform to represent Phoenician. At least there we find the oldest mention of the minor god Yahweh. How the folks in the hill country married Ashara off to that nere-do-well is still a mystery.
I don't think people asked politely before mugging someone and stealing their gods. Just ask the Egyptians how it went with the Hyskos and Seth
That is why I pointed out only believers claim it is other than Phoenician.
There are actually differences, but basically, yes, they are essentially dialects of the same semitic language. Sorta like Spanish and Portuguese.
But they were not monotheists. The first simple declarative sentence for monotheism is found in the Koran. The Judeans were never monotheists unless you want to insist there really was a famous person named Strato who had towers in Tyre, Jerusalem, and Caesarea. BYT STRT Temple Astarte next to the Antonine Fort in Jerusalem which was on the "temple mount" and all kinds of things follow from that.
We have only one god is not the same as there is only one god. The Christians used the term true god but the proper translation is true and false god in the sense of true and false patriot or lover. It meant not fickle as were the other gods. I believe in one god has the sense of faith and trust and is definitely not, I believe there is only one god. In fact the entire concept of refusing to worship other gods is nonsense if they in fact did believe there was only one god.
But if the Judeans had been monotheists they would have been the only monotheists in the entire world. They would have been the strangest people in the entire world. It would have been the one thing that made them different from other savages on the periphery of the empire. But no one mentioned it.
Well, yes, the consolidation into only one god would take some time. And yes, in a sense they were strange, but in another sense they weren't. Most ancient worship was actually monolatrous or henotheistic. We have tablets where one god is put above all others, or even denying all others, for every single god in the Sumerian pantheon, for example. One city or region or population group worshipping a god while (barely) tolerating the others was really the norm, and true polytheism was actually the rarer case.
Before Islam the most the Christians did was demote the pagan gods to demons when they had to explain how they could work cures and answer prayers just as well as Jesus.
I'm not sure how that's different. And, really, proclaiming the other gods false and their miracles and christ-like sons as done by Satan (centuries in advance, to confuse the Christians when the Christ finally happened, apparently) is at least as old as Justin Martyr, almost 5 centuries before the Islam.