That is probably true CPU wise, I am just worried about memory. If each process is 50 MB and you have 12 servers and 9 processes per, that is over 5 GB. If my machine only has 4 GB of RAM some of those processes must be in the swap file.
django also has a sites package, so you can run multiple sites per django instance. it's less encapsulated but if you run a high number of websites with a low amount of traffic each it makes a lot of sense.