Yes, well people do tend to send everything they have. I expect it you were in an accident in let's say an islander, which is a light aircraft by definition, you might be a bit miffed if you had to wait while the ambulance shuttled the other nine victims to hospital. This unfortunate pilot got the full response, sadly for him it wasn't required.
I did once collect the full trio of, in that order, ambulance, police car and fire engine following a field landing in a glider, with no damage to either self or glider. They went away when I explained it was normal for gliders to do this, and no, it wasn't broken, the wings were supposed to come off so it would go in the trailer. Which at this point was trying to get past the fire engine.
Don't expect a well meaning witness to do a full report, they are doing their best to help someone, or possibly several someones, in serious trouble. They probably aren't standing right next to the wreckage, the person taking the call probably isn't clairvoyant, and they can call the extras back or onward if they aren't needed on site.