Interesting analysis. I must admit I would have thought bot vote %age would be higher.
In terms of finding out more about manual curation, it would be interesting to know what percentage of votes are cast via auto-voters.
This would be a more difficult analysis and would require somehow picking up votes always made at the same time after posting between the same two parties.
No idea how to do that, and I have no problem with auto-voters - but it would be interesting to know.