“Shallum was the son of Shaul. Mibsam was his son. Mishma was his son. The sons of Mishma were Hammuel, Zaccur, and Shimei. Shimei had sixteen sons and six daughters. However, his brothers did not have many children, so that all their family did not multiply like the Judeans.”
Here there are 5 generations descendent from Simeon via Shallum who must have been the most important of Simeon’s sons. There were over 15 people with the name of (1) Shallum, including a King of Israel (743 BCE). Interesting enough both (2) Mibsam and (3) Mishma were the names of the sons of Ishmael. I am not sure whether this is a coincidence or an attempt to say something here. This is the only mention of the name Hammuel, the son of Mishma. There are 5 or 6 people with the name of Zaccur. There 16 different biblical figures with the name of (4) Shimei. This Shimei was very productive with over 22 children. However, his brothers and their families did not multiply like the family of Judah. This might be the reason that the family of Simeon will blend and become simply Judah.
“These are their genealogies. The first-born of Ishmael was Nebaioth, with Kedar, Adbeel, Mibsam, Mishma, Dumah, Massa, Hadad, Tema, Jetur, Naphish, and Kedemah. These are the sons of Ishmael.”
This section is based on Genesis, chapter 25, with has exactly the same names. Ishmael had 12 sons who then became 12 princes, much like Jacob who will have 12 sons. Ishmael was the hard luck outcast, but important because he was technically the first born of Abraham. Among his 12 sons, (1) Nebaioth will be the father of the people who settle in Edom. The descendents of (2) Kedar settled in the Arabian Desert. (3) Adbeel settled somewhere southwest of the Dead Sea. There are two other people named (4) Mibsam and (5) Mishma in the bible. There are a number of places named after (6) Dumah, the most famous on the Syrian border. The (7) Massa descendents settled somewhere near the Babylonian border. (8) Hadad frequently turns up as a name of some princes in Edom. A town in Syria is named after (9) Tema. (10) Jetur, (11) Naphish, and (12) Kedemah seem to be associated with the Hagrites. They mostly settled in the Arabian Desert. Thus you have the 12 tribes or sons of Ishmael just like there will be 12 tribes or sons of Jacob.