Yes, the last king in the "house of david" (which refers to a lineage not a kindgdom) according to the bible was in 930... There was not "house of david" alive after 930 according to the bible ..
So yea what your saying makes no sense.. like if there was such a kingdom and the people and villages somehow still existed there was literally no "house of david" .
so no matter how you split it your theory makes no sense (not to mention is not supported by the historians and experts for many of these same reasons)