bit of an update for you guys (not trying to derail or take over the thread) but this method also works for new factions. The editor in game is ok...if you like kingdom..but ive created an empire fraction, with all the bonus stuff. Plus you can also mod your created units, but those still need the materials and such.
ive modified my cities to have a space of 100 instead of 50..lots o room now
Sir, where is the city size file located ?