Israel Has No Part In Closing events...
The Apostle James knew that Israel had been redefined because he calls the believers in Christ the twelve tribes of Israel. (See James 1:1 and 2:1.) Of course, current saints do not know which tribe is theirs, but this information will be clarified when the time comes for them to enter the Holy City.
(By the way, no one belonging to the Jewish race today knows their biological tribe of origin either. The Roman army destroyed all of Israel’s genealogical records in the first century A.D.) So, biological origin, temple services, sacrificial offerings, circumcision, and all of the Old Covenant terms and conditions mean nothing to God today. (Galatians 2–4, Romans 2:28–29, Hebrews 7–10) God has terminated the Old Covenant, with its promises and prophecies, and has declared it null and void because there is a New Covenant, a new group of trustees and new promises and prophecies.
There is no NT support for your Replacement Theology any more than two covenants. First, not all Israelites are Jews. The history and future of the northern kingdom differs from the southern; you only account for the southern. James did not redefine Israel; he addressed the scattered tribes in the first century, not the Gentiles. Peter and James' ministries were to the circumcised, while Paul’s was to the uncircumcised,
But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter; (For he that wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles. (Galatians 2:7-8)
Secondly, the NT affirms that God has not “cast away his people which he foreknew” and that “the gifts and calling of God are without repentance” (Romans 11).
And last, Zechariah prophesied after the return from Babylon, so he prophesied of another sowing “among the people,” specifically the Northern Kingdom of Ephriam,
And they of Ephraim shall be like a mighty man, and their heart shall rejoice as through wine: yea, their children shall see it, and be glad; their heart shall rejoice in the LORD. I will hiss for them, and gather them; for I have redeemed them: and they shall increase as they have increased. And I will sow them among the people: and they shall remember me in far countries; and they shall live with their children, and turn again. I will bring them again also out of the land of Egypt, and gather them out of Assyria; and I will bring them into the land of Gilead and Lebanon; and place shall not be found for them. (Zechariah 10:7-10)
Hosea prophesied they would be mixed with the Gentiles,
Ephraim, he hath mixed himself among the people; Ephraim is a cake not turned. (Hosea 7:8)
Christ's parables, like the scattering of the good seed, were not precipitous but have their origins in passages like Ezekiel 34; Zechariah 13:7; Jeremiah 31:1-2, 27-28; Isaiah 49:5-7; and Hosea 2:14-23.
The true Israel, Ephriam, is hidden amongst the Gentiles, represented in the parable of the treasure “hidden” in the field. Ephraim is the “pearl of great price” and the “good” gathered into vessels.
Ephraim is the “nation” bearing the fruit of the vineyard, which includes the Gentiles (Matthew 21:43).