I'm not sure who aided in constructing this mental representation for you that the number of cops is directly proportional with the scale of conflict that's about to happen.

I'd challenge that view by claiming that if the threat is of someone holding their family hostage threatening to kill them (just a guess at what these "swatters" might say to the dispatcher to get cops to actually kick in some doors, I don't know what their state-of-the-art accusation is), then sending one cop car, poorly equipped, sounds a bit silly for multiple reasons.