This run relies on getting 4 Wizards in the nearest ruin, then expanding outward in all directions with Wizards and Griffins. After this run I found a more efficient route that reaches >40 cities by the end of turn 5, which can be completed in 4:2x. However, the low probability of successfully completing this run (i.e., no Wizards dying), combined with the low probability of getting 4 Wizards in the nearest ruin, means the odds of getting a time in the 4:2x range are on the order of 1000 to 1. After weeks of practice and many hundreds of attempts, I decided to give up and move on with my life. So, there is definitely room for improvement, for those willing to go through the pain. :-)

Meanwhile, for those looking for a good run that can come in under 6 minutes, this can be done by getting Wizards and/or Dragons in one of the two nearest ruins. The odds of this are around 8 to 1 -- much more manageable!