The Persian Wars
1000000 coins are required for the rank Merchant Prince in this episode. Bonus or special points can be accumulated towards this achievement for weapons and armor trading, “it does not matter where.”
This is a difficult game to get a good quick cash flow, to be able to start trading Bronze Sword which are available 50 years into the game.
The tactic of the AI traders is to view town markets as an initial source of wealth, then let them decline as they focus on the gold coin pile generated by swords and armor deliveries. The player focus too needs to be on weapons creation and delivery,not market house growth.
Tin and Copper are only sourced raw on the Aegean Sea and Persia maps. The same occurs later with Iron.
If you don't have the coins to add a stable to a barracks location or vice versa, to double sword demand, look across the regional maps for markets that will encompass both structures. The two together often mean a later arsenal or fort could appear too. If you have the coins create markets as the game progresses that include a barracks, stable, arsenal and fort or castle. This allows for four swords to be delivered to a market by faster drays.
Cuirasses when available really hit into your copper and bronze ingots stocks. However, persist as the profits are high. Once Iron swords enter the game around 350 BC, your copper is freed up for Cuirasses which remain in the game until the end. So even if you couldn’t meet the early demand, you hit high prices of 2000+ each, late in the game.
Iron is plentiful and often in places where a market radius can get three mines in .Build your smelter and iron smith with the iron mines. Iron swords are produced fast and are demanded quickly.
Late game technologies like Paper and Gold Rings are a distraction, keep the focus on the military hardware.