I wanted to comment on the question you posed about why Galilee of the Gentiles is called such if the region was populated mostly by Hebrews. It seems that Matthew (detail-oriented), vss. 4:14-16 is repeating a prophecy Isaiah gave in Isa. 9:1-2. In that prophecy, the word Gentiles is replaced by Nations. It may be that by the time Jesus began his ministry, there were mostly Jews in that region.
I wanted to comment on the question you posed about why Galilee of the Gentiles is called such if the region was populated mostly by Hebrews. It seems that Matthew (detail-oriented), vss. 4:14-16 is repeating a prophecy Isaiah gave in Isa. 9:1-2. In that prophecy, the word Gentiles is replaced by Nations. It may be that by the time Jesus began his ministry, there were mostly Jews in that region.