Outpost mines
In SOD1, outpost had the option to get fuel mines to expand radius and was good for stopping hordes. Bring it into SOD2 to make the outpost an actual safe spot. In a zombie wasteland, you would build barriers and traps to prevent zombies for getting to the base or at least give warning to the approach of them. I have been to a few of my outpost with 1 to 3 hordes in safe space. I wouldnt give them mines without getting them ( paying resources for them) nor expand the zone as it is big enough.