Do not forget to use the Lucky Wagons. An easy way to find them to enable the doyousee code. Then on the mini-map, click on the "Toggle Resources" button. This will leave you with your town and the enemies colors on the map as well as some black dots. Go and look at the black dots. If the Lucky Wagon is there, send a Knight or the nearest unit the wagon. Even after reaching the population limit, it will still allow you to use them.