Alma 49
I’m sure that Amalakiah helped to convince the Lamanites to go to battle by promising to give tnem the same kind of armor that the Nephites had used against them before. Also, the people probably more willingly accepted the Zoramites as leaders in the military because of their knowledge of the Nephite defenses. Moroni, on the other hand, was designing defenses not only for the individual locations, but for the overall strategy. He fortified Ammonihah enough to scare them and then focused his preparations on Noah because he knew that would be their next target. I’m sure he had many other citied being fortified, but with those two in that order the Lamanites would know that they would have no idea what to expect and they would eaither withdraw or attack one of those two cities.