Cultural: Here is the next indication that the population is larger than twenty four adult males. As with the early Nephites, the Jaredites establish a king early in their history, earlier than the slow process of generational population expansion would create a population base that could support a king, regardless of the nature of that king.
Given a plausible Jaredite immigration timeframe of between 1600-1700 B.C., it is quite likely that the establishment of kings in the second generation is somewhat of an exaggeration of the nature of leadership. Certainly an inherited ruling line was established, but the archaeological history of Mesoamerica does not see strong development of kings until about 1200 B.C. The Jaredites could easily be precocious in establishing some form of hierarchical cultural system, and indeed the greater stratification of society is known from at least 1500 B.C. onward.
It is plausible, however, that what we have in Ether’s record (and it is important to stress that it is Ether’s record) is a backwards understanding the kingship of the Jaredites being attached to the earliest founding fathers. There has certainly been enough time passed by the time Ether writes to have had history reconstruct itself in this manner.