Observations on Book of Mormon geography

From the time the Nephites move to the land of Zarahemla in Omni 1:12 and until the coming of Christ in 3rd Nephi, the Book of Mormon geography is consistently and repeatedly describing several cities and areas and even their relative locations.

For instance, the city of Gideon is first mentioned in Alma 6:7. We learn that it is named after a person who is first introduced in Mosiah 19 and it is mentioned again in Alma 30:21, Alma 62:3 and Helaman 13:15, each time indicating that the city is close to the city of Zarahemla.

In particular in the "war chapters" in the last part of Alma we learn the names of many Nephite cities, which in many cases are repeated. It might be reasonable to expect another repetition of those city names in 3rd Nephi 9, where the voice of Christ laments the destroyed cities. But apart from the cities of Zarahemla, Moroni and Jerusalem, we only hear of new city names, like Onihah, Mocum, Gidiandi, etc. After that, the Book of Mormon geography doesn't seem quite the same. There are a lot of new city names in Mormon as well. What is the explanation for this?

First of all, it is important to note that the record keepers from Mosiah-1 to Nephi-3 all lived in Zarahemla. The record is written from their point of view and the events are typically described in the land southward. Whenever someone goes to the land northward (that is north of the narrow neck of land), they disappear from the record. For instance, we learn about migrations to the north in Alma 63:4 and Helaman 3:3, but we don't know much about what happens to these people. In the case of Helaman 3, Mormon even states that they also kept records, but they are apparently separate from the records Mormon is abridging from.

Secondly, when Jesus speaks to the Nephites, the point of view has shifted. It would not make sense if he only spoke to the people in the land southward because we know there where Nephites also in the land northward. In fact, "there was a more great and terrible destruction in the land northward", which likely caused the destruction of even more cities, -cities we have not yet heard of.

When Jesus comes, he comes to the land Bountiful which is by the narrow pass, between the land northward and the land southward. The city of Zarahemla has been destroyed by fire, so the record keepers are not living there anymore. Even though it's rebuilt in 4th Nephi 1:8, the record keeprs don't seem to live there. The last record keeper in 4th Nephi hides the records in the land Antum, north of Bountiful. Mormon is originally from the land northward. (Notice how he is carried into the land southward when he is 11 years old in Mormon 1:7). Later as a war captain his armies are driven to the "north countries" (Mormon 2:3) and we again learn new city names like Boaz, Jashon and Shem. There is no more Gideon, Mulek or Ammonihah. Which is also expected, because the point of view has been shifted from record keepers in the land of Zarahemla to Mormon who is trying to withstand the Lamanite army in the hitherto unknown land northward.

Much can be said about consistency in the Book of Mormon geography, but these observations show that even when things don't seem to make sense on the surface, a deeper study reveals geographical consistency all the way throughout the book.