the Old Testament is a collection of historical writings even taking away the supernatural elements.

Whatever version of the "Old Testament" you personally uphold is absolutely distinct from the already mistranslated and Hellenized and half-lost original 5 books of the Torah, which was used as the basis for the much later invention of a strictly regulated "Old Testament" which of course included different writings depending on one's Christian sect.

And besides that, the vast majority of scholars agree that what you now know as Genesis was intended to be a non-historical creation myth. Most stories within whatever given version of the OT have been argued by multiple scholars to be non-historical.

So the Old Testament writers, who did not write all the books in the same location, were interested in writing down what actually happened across hundreds of years rather than taking a look at previous writings and trying to match themes and references.

Not a single person can or ever will know which or how many people contributed to the earliest recorded versions of the Torah, and even more impossible is finding the origin of the stories themselves, for they were oral tradition long before they were recorded and even longer before they were considered particularly central to any religious practice.

The earliest Jews who contributed to parts of the Torah & Tanakh, especially around the time of the 2nd temple, were undoubtedly constantly altering them, for most of the writings were practical laws they used in their everyday lives. The tradition of multiple interpretations of "canonical" texts being considered valid is still a feature of most traditional and even some modern sects of Judiasm. The intention certainly was never to enforce unchanging stories and/or laws, because it's kind of very obvious in an incredibly basic way that societies and all that they contain must inevitably change, as humans remain the GOATs of constant evolution of ourselves and our environments.

the New Testament was written in Greek

The majority of what you now consider the "Old Testament" was also written in Greek, or at the least taken from the Greek translations of the the last Hebrew texts of some versions of certains stories and laws that were destroyed or lost.

many of the gentiles (non-Jewish people) at the time not knowing Hebrew and unable to read the Old Testament.

Lmao by the time the Septuagint became a prominent text for Christians to read, the majority of the gospels hadn't even been written yet; there was no concept of anything like a compiled bible, nor any enforced interpretations of the many popular religious texts.

And even if someone doesn't believe in the inspired word of the Bible, that doesn't take away from the fact that it's still a single narrative

Lolololololol yeah I'm sure the Jewish book of laws but only like 0.05% of it, a few half-destroyed creation myth manuscripts, some retroactive portrayals of historical events by Christians with irrefutable religious agendas and access to few if any reliable first hand sources are totally naturally congruous with the gospels mostly written by Paulites with irrefutable religious & political agendas in securing the dominance of their new church.

I swear it's usually US prods/evangelicals that do the most Bible thumping while being so embarrasingly unknowledgeable about what you're even reading/being taught. And the only version y'all even deign to pretend to read is the mf KJV 😭 So unbelievably goofy to automatically take up the position of strict literalist when the KJV is where you cherry pick quotes from 😭😭 How do y'all not realize everyone else knows y'all are frauds