megistatos
Warlord of Mars
This is not quite true. Take a piece of paper and draw the cultural boundaries of three rings of towns with 0 culture. Count the number of tiles, a square with the sides 21 tiles. This comes to 441 tiles. Subtract the 49 tiles occupied by towns and divide by the number of towns. The number of tiles available per town comes to no more than eight (8).
I was referring to Chamnix's idea of giving each city 12 tiles. Although this doesn't work with strict CxxC placement, I was thinking more along the lines of a tightish placement.