The number of casualties from a singleton jihadist depends on target choice, and creating extra victims from any resulting panic stampede.
Or, a singlton can grab attention with a hostage situation, but in that case sleep wears them down and allows HRT to get them.
How organized are they? I don't know. Will it all be independent, spontaneous action? I think there will be some of that, maybe alot. But I also believe they will have many well organized and planned critical hits prepared to go off during the midst of the other...thereby dividing our resources and distracting us before their dedicated, a-team (if you can call them that) hits.
BTW, my post 37 was in response to the democratic snipes and attacks on GOP offices. I personally do not count those events in the same class as this.