Five victims in two vehicles...two rescue units and four ambulances plus one medivac that loaded at the scene looks like they had just what they needed to get the victims out and transported.    One rescue to work on each vehicle, then enough beds to take everyone away as soon as they were ready. What do you want to happen?  One rescue unit and one ambulance, and everyone else just has to "wait their turn?" Fire and LEO response is pretty much standard for multiple mva.  Usually see two fire units dispatched to an injury crash...whether one dept or two depends on availability when dealing with rural volunteers.  Reality out in the sticks is that you are going to have to have multiple services involved to get that kind of response. 

Too much is better then not enough.