When you say Israel will be on Earth during the Millennium do you mean Israel will still be a distinct nation during that time, made up of Jewish believers? Does this mean that gentile Tribulation survivors will live in other parts of the world? Isn’t Jerusalem where Christ will reign from?
I think the Bible clearly describes a nation called Israel living on Earth during the Millennium in the Land God gave to Abraham (Ezekiel 40-48). This will be a Jewish nation populated by tribulation survivors from the 12 tribes of Israel and resurrected Old Testament saints. The Old Testament name for the Millennium is the Kingdom Age and is when all the remaining promises to Israel will be fulfilled. Israel will not only be a nation on Earth but will be the world’s preeminent nation and God Himself will dwell in their midst again. Rev. 22:3 tells us the Lord’s throne will be in Jerusalem on Earth.
Gentile tribulation survivors will re-populate the nations during the Millennium. Of these, I believe the Bible only mentions Egypt and Assyria by name (Isaiah 19:23-25).