I want an overabundance of firefighters. On average my town needs 0. However a couple times a year there is a fire and then we need 30 for a couple hours. We solve this by hiring 30 full time fire fighters so that 10 are always on duty, and when there is a fire we call the on duty fire fighters from the other nearby towns to help.
(The above numbers are only rough estimates, close enough for discussion, but not even close to right)
(The above numbers are only rough estimates, close enough for discussion, but not even close to right)