Deuteronomy could be propaganda by xenophobic Levitical scribes ("Deuteronomists"), using true segments by Moses, but compiled during the reign of King Manasseh and planted in the temple to dupe young boy King Josiah to begin a xenophobic regime, an anti-Melchizedek, anti-temple, anti-prophesy, anti-theophany, therefore anti-proto-Christian reform that ultimately led to Jerusalem to be razed three times.
When they discovered Deuteronomy (the Second Law) in the temple and took it to the young King Josiah, he didn't believe it at first, he never heard of it. In fact, not a single patriarch or king had ever obeyed all the Deuteronomic Laws, Josiah was the first king to do so, and for all of his faithful efforts, and Deuteronomy's promises that obedience to the Laws would cause Israelites to prosper, fate forsook him on the battlefield and his kingdom was ultimately brought to ruin.
And all the Deuteronomist scribes could do to explain away this fact in the Deuteronomic history books of the Bible they wrote, was to blame it on the great wickedness of his dead predecessor, King Manasseh. Deuteronomy was not written by Moses in its current form, some parts are indeed ancient and valuable, but it was ghost written. Or are you telling me Moses was writing that book when it gets to the part where he died?