I assume by "Goyim" you mean non-Jews?
You should assume what the word means.... the nations... non Hebrew.
You went to great lengths to dig out some references to delineate who you think Jews are. When all you had to do is read who they are in Ezra and Nehemiah. Jew and Israel are interchangeable terms that mean the same people. Strong's concordance is not scripture, even though some use it like it is.
First off, many of the northern tribes migrated south and joined with the southern tribes. There are many instances of that in 2 Chronicles, including one event that occurred 100 years AFTER the northern kingdom had been taken over by the Assyrians, showing that the Northern tribes were not "lost".
Therefore, when the Southern Kingdom was taken over, people of all the tribes went into the Babylonian exile.
When allowed to return, the remnant that Ezra brought back from Babylon, he referred to them as Jews 9 times and Israel 40 times. Reflecting all the tribes.
The remnant that Nehemiah brought back from Babylon, he referred to them Jews 11 times and Israel 22 times. Reflecting all the tribes.
In other words, by the time of the end of the Babylonian exile, the term Jew and Israel had become interchangeable terms for the collective 12 tribes. And it remained that way thru the time of Yeshua on thru to today and affirmed as such by Ezekiel. The 12 tribes were only delineated by land portions established when they conquered the land after coming out of Egypt. When those land portions were eliminated, the people of all the tribes became a collective group.
The division of the tribes no longer is an issue. They are all of Jacob (Israel). The only way one could argue that the northern tribes are "lost" is in reference to their being commingled with the southern tribes with no more land delineations to segregate them.
Even Paul uses Jew and Israel interchangeably to reference who he considered his physical brethren. He even calls himself and Israeli while at the same time distinguishing that he is of the tribe of Benjamin, Judean.
Philippians 3:4-5 (NASB) although I myself might have confidence even in the flesh. If anyone else has a mind to put confidence in the flesh, I far more: 5 circumcised the eighth day,
of the nation of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as to the Law, a Pharisee;
Those references about those in Judea fleeing is a reference to a specific land area, not a tribal delineation. Jerusalem is in the area of Judea, and Jerusalem has always had members of the various tribes within it over the millennia.
Some should be careful that in straining at a gnat, they don't end up swallowing a camel.