What you say may be the truth, or it may be the official line. Modern Jews may say that, but is that just what they have been taught to think?

There is a well known saying “the winners (re)write the history”.

As you say, the Jews are associated with the kingdom of Judah, which was distinct from the Northern kingdom of Israel. Were they not at war with each other at some point? You appear to be alluding to this in your response.

Even at the time of Jesus, there was still a strong distinction between the Jews and the Israelites, if the Gospel of John is to be believed.