I think you are asking specifically about the enforcement issues that derive from neighboring populated counties with different policies? Neighboring counties

I think you are asking specifically about the enforcement issues that derive from neighboring populated counties with different policies? Neighboring counties can and should coordinate to address this, possibly choosing to enforce the same policies even if they have different infection rates, as they did for the initial lockdown in the bay area. This doesn't prevent us from using a county-by-county approach in other areas.