Obviously, the larger the municipality the broader the services and deeper the pockets. A dedicated set of emergency services departments reflects the greater potential for public danger due to density, industrial base, transportation corridors, etc.
A township of 5000 has fewer resources but a corresponding lower risk level. Lower doesn't mean non-existent. Weather events don't discriminate but the impact and response of having to accommodate 100 people vs 10,000 is different.
Easier to execute if they are a core drawn (borrowed, seconded, etc.) from other parts of the same organization then return to their positions. Dismissing them to the job market means you may not get them back, or at least not when they are needed. I'm not a fan of using consultatnts for this. They have a different motivation than staff personnel, have to learn the organization and issues, and I suspect quality expertise in disaster management is limited and, for that reason, pricy.