For each new settlement you have the choice of how ruthless you wish to be. If you passively approach you can recruit 25% of populace and leave the town relatively peacefully. This means they will continue to gather resources which can be accumulated at a later date. A neutral approach recruits half of the citizens while aggression may significantly expand your army but it will leave no one left to build resources. As with so many RTS games the best approach to ‘PowerMonger’ is a balanced one. You need to be mindful of your army's current and future needs. Expand too quickly and you will not be able to feed your army, but too small a force will not allow you to successfully take new territories. According to the developers a player "must learn to balance force with restraint, and the requirements of the day with the needs of days to come. Only then shall you be the ultimate Power Monger".
Its detail that's not needed though. A player would have to have a great deal of time on their hands to click on each person to determine their heritage and back-story. It may rain and snow but while they do technically impact the action by slowing down your army as there's no way to control the weather you literally soldier on regardless. So many little details and elements of 'PowerMonger' are so easy to miss you may be left wondering why Molyneux even included them in the game.