According to the thinking of John Sorenson, the Amlicite zone was surely downstream (from the local land of Zarahemla) along the river Sidon. Had it been upstream, the Amlicites could simply have joined the Lamanite army up there (before the battles ever started). . . . Most logically the Amlicites occupied the area down-river from Zarahemla possibly called "the most capital parts of the land" (Helaman 1:27). [John L. Sorenson, The Geography of Book of Mormon Events: A Source Book, F.A.R.M.S., p. 230]
In John Sorenson's Mesoamerican geographical theory, the area down-river--specifically the city of Ammonihah--is associated with the site of Chiapa de Corzo. This was the largest city within the entire central depression at this time and the heart of that downstream sector. It was larger and more prosperous than Santa Rosa, the proposed site for the city of Zarahemla. No wonder it might rebel against overlordship located upstream. Furthermore, at this period of time (the second century B.C.) Chiapa de Corzo maintained clear-cut cultural ties to the Mayan speakers to the south, that is to Lamanite country in our Book of Mormon terms. An alliance between Amlicites based in the Chiapa de Corzo area and the Lamanites in Nephi (highland Guatemala) would have formed a vise, putting pressure on the Nephite center. Of course, we cannot say for sure that this geographical arrangement is how things really were. No one knows enough facts yet to be sure, but it very reasonably could have been so. [John L. Sorenson, An Ancient American Setting for the Book of Mormon, F.A.R.M.S., p. 197]
According to John Tvedtnes, the contrast between Amlicites and Nephites in Alma 2:11 implies that the Amlicites were, in fact, not Nephites. The leader of the Amlicites was a man named Amlici, who was of the order of Nehor (Alma 2:1). The order of Nehor is most associated with the city of Ammonihah, where the judges, lawyers, priest, and teachers were of this order (see Alma 14:16-18; 15:15: 16:11). If the people comprising the order of Nehor were Mulekites, this would not only explain the phrase "and the remainder were called Nephites," but it would also explain why in the story of Alma's visit to Ammonihah, a man named Amulek, who lived in that city, took pains to specify that he was a Nephite (see Alma 8:20; 10:2-3). [John A. Tvedtnes, "Book of Mormon Tribal Affiliation and Military Castes," in Warfare in the Book of Mormon, F.A.R.M.S., p. 300]
Note* On the other hand, if all the Amlicites were located strictly downstream, then the reader should wonder why these Amlicites seemed to find no problems in joining an invading Lamanite army upstream at just the right time. Was it just a coincidence that the Lamanite invasion came toward the local land of Zarahemla not only at the right time, but from the right place in order to join with the Amlicites? I think there probably was an already established bond between these Amlicites and "Lamanites." The reader might look to "the order of Nehor" as part of the reason for that bond. [Alan C. Miner, Personal Notes] [See the commentary on Alma 1:15; 2:15] [See Geographical Theory Maps]