The most obvious way is to base the elements on what the story needs. Wounded players will find a doctor to help keep the game moving, or wont to keep up the tension. The required resource they must return to their homes will be availible when the campaign is ready to reach a climax, and not just a random roll on a loot chart.
For those who don't mind doing a bit of research, basing towns on real life locations can be useful. A game master can chose a local city that all the player are famialr with - and thus abel to use real landmarks and lcations as points of refrence, and have a good idea of what is around. Conversely, the GM could pick an area in a diffrent part of the country - which puts the players in unfamialr teritory - services like "Google Maps" can give acurate distances or infor about what they might encounter.
A more complex way would be combining the scarcity rules with a series of metrics. In turn, these are further sub-divided into three sub categories - Required, Helpful, and Advanced. So for example - all towns will have some population, but not all of them have doctors and mechanics, and veteran soldiers are found in only a few that have properly established themselves.
- Population - Number of people available to work
- Defense -
- Location - Safety and natural resources of the area
- Resources -Goods, services, and benefits of the town
- Stability - law enforcement and government planning
- Skilled Labor - Doctors, Mechanics, Chemists and so forth.
- Body Armor -
- Trade Goods - valuable commodities like micro-fac goods, medicine, chemicals.
- Soldiers -
- Rifles - People can defend themselves with handguns or improvised weapons, but better equipment is nice.
- Transports -
- Military Vehicles or Power Armor
- Veterans - People with advanced knowledge of combat form either pre-Event or learned survival
- Infrastructure - Working electricity, pumped water, SPHERE connectivity.
The required attributes are phased scarcity.A failed roll indicates something is going wrong with the basic functioning of the outpost, and the area is degrading. For example, a failed location roll means might mean they are using too much lumber or polluting the water, rendering the area a bit less liviable. Meanwhile, defenses degrade as opponents learn the layout of traps and adapt, or damage to walls reduces their integrity.
Conversly, the advanced ones are most likely binary - either they have the goods you're looking for, or they don't.