Jesus, is that visualization supposed to help? I stared at it for minutes and I still don't really grok it. Seems like it is trying to channel a similar method as the Napolean March: http://bryanrulli.files.wordpress.com/2011/05/tufte_napolean... But failing completely at it. In any case, is this a common type of visualization now? Maybe with some experience it becomes easy to grok what is happening?
A dot chart would have been substantially better. I haven't seen that sort of visualization before. It's probably a mistake to try to show the relative size of each group in the same picture as the absolute size.