I have the same in 15mm as a simple linear campaign based on some central characters (Dukes of Hazzard types). I was simply going to start off with the good old boys finding some greys in a field with cows, so they bring out the shotguns and “get stuck in”. Then depending on the result either chase the greys back to the mother ship in a forest or then be chased back to town.
The forest stage would find Hunters, Dope growers and survivalists to aid the farmers etc. Heading back to town would be Cops, national guard, Scientists and Digruntled postmen etc.