Depends on a lot of factors related to the environment, i.e. pollution types, viability of water treatment, food sources and what their growth is reliant on, equipment and what their maintenance is reliant on (i.e. parts/consumables ideally not reliant on regions in heavy conflict).
I've never been in a war zone but I have been in one of the country's worst natural disasters (along with several smaller ones) and what I learned from those experiences is not to trust anyone who refuses to understand the importance of fluid decision-making in complex life or death scenarios, instead rigidly adhering to a fixed plan they had developed long before the emergency situation happened. It ends up slowing them down far more than anything and creates loads of avoidable problems in the name of consistency.
That's not to say one shouldn't have a plan but if it relies on taking route A to escape and route A is on fire, the people who blindly say "STICK TO THE PLAN" without recognizing that the plan requires adaptation, they're not to be trusted because they possess a theoretical understanding of the situation, not a practical understanding.
Far too often people who confidently think their plan A will work, end up dying because they foolishly downplayed the need for adapting/abandoning their plan in the face of impending doom. Wildfires in particular have resulted in entire families burning to death-- wealthy families who were convinced their various expensive, extensive precautionary methods were foolproof but learned the hard way that mother nature can very quickly make a mockery of the measures humans take.