Thanks, Unclued (post 33), for clarifying what exactly had to be done to the three entries. With that help I have now tied everything up, I hope. Thanks to others also for little nudges on the way, without which I’d probably have given up.
The preamble refers to a fatal affliction suffered by “only two-thirds”, i.e. 6 of the 9, who lose their heads. But the other three seem to be totally exterminated!