As indicated in the essay on the use of numbers in the Book of Mormon, these are suspicious numbers and may not reflect real troop strengths. The difference is to neatly packaged in symbolic numbers to accept without question. In particular, the final contrast between 4000 and 2000 would not only mean inferior numbers, but perhaps even symbolically inferior forces, and 4 is the Mesoamerican number of perfection. Mormon would be using the numbers to indicate his relative disadvantage, one that was far greater than simply 2000 men.
In spite of whatever disadvantage Mormon might have had, he finally has his first victory over this invading army. This was only a battle, however, not the war. Mormon and his forces had retreated far north, and had given up large tracts of land. Although this is the beginning of hope, it is far from the conclusion.
Chronology: The three hundred and thirtieth year would be 322 A.D.