I've updated my NM graphs. There were some cases where the advocate and AM entries in the NM database didn't match the Debian user name, so some people appeared with two different names. There are still lots of unconnected components in the advocate graph, which is because the "advocate" field in the NM database was added only later, and the older entries all have "sunset" as advocate which I skip when generating the graphs. If you want your advocate listed, or have advocated someone back then, please tell me so I can add that to my scripts.
Wouter mentioned that besides neato there was springgraph to create this type of graph. Coincidentally, I happened to adopt that package last week and as upstream hasn't updated it for some years, I'm probably also its new upstream. However, I haven't managed yet to produce any useful output on the NM graphs with it yet (it's still chewing on advocate.dot while I'm writing this), so I'll stick to neato for the time being. (Since graphviz is now free, I don't have any qualms against doing so.)
On a sidenote, I'm wondering how many software patents I'm touching with these scripts in our fine banana republic.