King Saul was a contemporary of kings Kamose and Amose—and lived not 540 years after them; similarly. King Solomon was a contemporary of Queen Hatshepsut, and Thutmose III of Rehoboam of Judea and Jeroboam of the Ten Tribes; and Amenhotep II of King Asa; Amenhotep III of Omri and Ahab; Akhnaton also of Ahab of Samaria and Jehoshaphat of Jerusalem, and of Shalmaneser III of Assyria. Therefore if we can compare material from two areas contemporaneous in my reconstruction but separated by 540 years in the conventionally written history, we may receive the carbon answer as to which of the two time tables is correct and which is wrong. The ivory of the Shalmaneser III fort near Nimrud and the ivory of Tutankhamen’s tomb must yield very close dates.
The Pitfalls of Radiocarbon Dating by Immanuel Velikovsky
Neighboring civilizations were in contact in antiquity. Just as through hikers on the Appalachian Trail today can walk 2,000 miles in a season, people could back then as well. With horses, camels and sailboats; it was even easier and quicker.
Royalty always faced the problem of finding the best marriage partners for their kids, and the economic and military advantages of joining with another kingdom are always strong.
Ancient Ethiopia and Yemen (and Israel) are close together physically. A days sail (more a matter of hours really, with slaves rowing). It would be common for them trade and visit regularly. Occaisional intermarriage and competing personal interests would probably draw them together and push them apart many times through history.