"Books Moses wrote?" What Bible are you reading? Moses gave us the Law, not the Pentateuch.
Whenever the writer wanted us to understand who had written these works, they would say something like... "even as it is unto this day." What day was that?
Genesis 19:37;
Genesis 26:33;
Genesis 32:32;
Genesis 35:20 ... and dozens of more.
It couldn't be Moses because when he died we read:
"And he buried him in a valley in the land of Moab, over against Bethpeor: but no man knoweth of his sepulchre
unto this day. -
Deuteronomy 34:6
That's kind of a funny thing for Moses to write about himself. Also consider
Genesis 14:14. How could
Abram have LITERALLY pursued Lot's captors all the way to a city that was named after Abram's great-grandson when Abram had yet to even have a son in the first place.
Also, how could Moses have "simply inserted 'Dan' for our understanding" when that particular city wasn't called "Dan" until about 120 years after Moses had died? See
Judges 18:29. Moses before "Dan" was even some place down around Gaza and NOT way up past the Golan Heights where they later migrated.
There's a whole history that the writers of Genesis knew about concerning the migrations of the Tribe of Dan that all happened long after Moses himself had died.
The writers never stop saying "unto this day" until they get to the book of Nehemiah. Why is that?