I think you are right; and what you're saying reminds me of a story from Malcolm Gladwell about the 1981 Traveller Trillion Credit Squadron tournament [1] that Doug Lenat won. He used some type of genetic algorithm (he never released his source) to find that swarming the challenger with many small boats would dominate as a tactic. Miniature swarms, which drones are cheap enough and more than capable for, are not a tactic that people are use to. I fear that a swarm could be terrible in its destruction if used to hurt people, individually targeted or for mass harm.

[1] http://www.newyorker.com/magazine/2009/05/11/how-david-beats...