I recently outlined a few tips for placing cities. And I have also extolled the delights of doing something counter-intuitive in Illyriad. So when I saw this city placement, I wanted to stand up and cheer.
All the usual rules of settlement-placement would suggest that you should leave plenty of room around your cities, that you should focus on high food production, and so on. What this guy has done is to igore all of that conventional wisdom, and do something brilliantly demented.
Think about what it would be like trying to Attack or Raid this guy. Every single city is on the same terrain – mountains. So he can optimize his armies to fight in mountains, and each city’s Reinforcements will be equally effective in every other city. And they can all be marched into any one of those cities in just a few minutes. That’s a potentially huge pool of troops, perfectly suited to the terrain, that can be shuffled between cities before any sneak attack could hope to strike - particularly since you won’t want to attack him with cavalry (cavalry + mountains do not mix well), so you’ll probably be using nice slow Swordsmen, giving him plenty of time to arrange a welcome for them.
And trying to Siege him won’t be easy. For most of these cities, you have no choice over what type of terrain to occupy for your siege camp – you have to siege from the terrain that your enemy has chosen, in this case mountains, which is the terrain all of his forces are optimized to fight on.
It might even be that one of these cities cannot be Sieged at all. (Volcanoes are “impassable” terrain, so cannot be Occupied. Assuming that also means you cannot put a siege camp on one, the middle city there has no valid squares for a siege camp.)
This is perhaps the single best use of terrain that I’ve seen in Illyriad – though if you have seen better, do Comment here, or Message me in-game! It is truly genius.