[Southernap]

Which once you have bought up the whole town and put your own people in charge. It becomes easier to win over regions as the mass of people interested in the NA grows. In bigger cities if they bought up businesses and put hide outs. Then they could be used to wrest control of neighborhoods that might then be used to build base of operations for taking over the whole city.

I could hazard, if you were to game it out, that the NA approach to the displaced persons in every region was winning the hearts and minds. Sort them with the idea of food, a place to live and a chance to be productive. Then have them attend some social gathering (say church or even a town meeting) with the push by the higher citizens start with the easy cult swaying by laying waste to the old government ("Those politicos in Capital City got us here with...) and start to talk about the wonders of what NA was doing to make things right ("We are giving folks like yourself good jobs right. Feeding you and your family? You feel safe from gangs and crime?"). Then depending on whether said person fits within the alignment of the structure. Sending them off back to work. Keep hammering home the old ways brought the world to this and that the NA has a new way to make it better. Folks will be swayed and they were start to spread the word themselves to others.

You might not even have NA operatives do dirty wet work on the new town's government, like what was alluded to in Airlords of the Ozarks and Allegheny Uprising. With the right charismatic citizen, one could say that even with the town doing right, the old government was part of the system that destroyed the sitcom and Friday night beers. That NA was offering a new way a way that would end war, stop crime, and put a chicken in every pot.
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Now all that said, how NA might get some heavy equipment might be interesting.

The number of incidents in real life where military equipment is sold on the grey or even black market by soldiers looking for some side cash is amazing. Similarly, seeing some things like armored cars that were supposed to be demilitarized and sent to storage yards. The shipments get mixed up or the trucks get stolen. Which yea its only an old V-150 or similar vehicle. That gets stored in some business bunker for later use by NA cells, against civilians, can give the NA an air of authority or even the superior hand to those that don't see the NA way as the new way.
I could also see some heavier crew served weapons like machine guns that are "damaged" getting misplaced on the wrong truck to head to the depot for overhaul and repair. Again end up in the local cell inventory.