Wearing my other hat as a bush fire fighter in Western Oz the policy of my Shire is to throw everything at the first report of a fire. Once it has been determined what the fire is then units not required can be turned back. However, everyone starts rolling. That way small fires don't become big fires.
On the other hand the neighbouring Shire policy is to send one unit out to check the fire report and call for additional units as required.
I'll give you one guess as to which Shire has had more out of control bush fires which require not only their own units to attend but a significant portion of neighbouring Shire units?