Again Mormon tells us little of the maneuverings during an entire year. We begin the year with Moroni in the west and Teancum in the east. Moroni does not arrive in the east until the end of the year. Certainly he was well occupied during that year, but Mormon gives us none of the particulars. Clearly Moroni had skirmishes if not all out battles with the Lamanites on the western front, and was able to stabilize the situation there. It was not a simple task, however, and required a year to achieve the point where he could afford to leave to assist Teancum.
The length of time that has elapsed also highlights the importance of the taking of the cities by the Lamanites. This part of the Lamanite army is far from their homeland, and thus far from supply lines. By taking the cities they can work the fields and have a means of growing crops in places where they can protect the fields. Thus they become their own supply line, and can hold out indefinitely.
It is also important to remember that the Lamanites held multiple cities, and that the cities could therefore reinforce each other. In Aztec siege operations, troops were sent to neighboring cities to make sure that they did not come to the aid of the sieged city (Ross Hassig, Aztec Warfare. University of Oklahoma Press, 1988, p. 107). Teancum would have been unable to completely cut off the inter-city aid among the Lamanites because of the number of cities they held. Teancum’s army would have been too diluted to have been effective.