In very rare instances, the Julii can trigger the Marius Event with Patavium. It's a fast-growing city (in the top three on my list for pain-in-the-a$$ cities to keep under control) and if conditions are right (ie. the Julii actually do something other than turtle after they take Segesta and Caralis) it will reach 24k somewhere around 225-215BC.

Too bad about the GC AAR...it was really an amazing feat to my thinking...if you are simply into finishing as fast as possible...