So far, I've mostly played the game as Carthage, so most of my ideas will be based on those experiences. I've started an 1.02 and more recently a 1.03 game, though I've played 1.01 as the Belgae and Rome too so far. But, basically, all factions in the underdeveloped western Mediterranean. I imagine (and hope) that the eastern theatre will play somewhat different But, I'm reflecting on my experiences, so I overlook things in my series of ideas, don't hesitate to point that out to me. I feel I like discussing this game
From what I understand so far, I see one quirk in how the trade-mechanic works. Being the mercantile republic Carthage is, increasing the trade range of Tunes/Carthage is actually not beneficial. Let me explain. Because you can not by 3th party resources and resell them to other factions, the main business a mercantile republic can do in this game is exporting it's own trade-goods to other factions (and trading internally offcourse), thus conquering foreign markets with our goods (in which Trade Acumen plays the leading role). This is handled by a chance-based formula, so that trades fluctuate. So far, so good. Now, if I upgraded my harbour in Tunes and consequently enlarge my Trade Range, I mostly see negative effects. Why is that? Mostly because trades happen if a region is lacking a resource and it consequently goes looking for it. So, increasing my Trade Range only increases the change of a Tunes import happening externally. This is because more regions (mainly external) with the necessary resource, say Flax as an example, come within range. Thus the chance increases of the trade happening external. A higher Trade Range doesn't improve my chances of exporting, even though a lot more regions are now within my range. Even though I can export to Italia, it's not happening because I'm not in their Trade Range (with some exceptions offcourse). It would make a lot more sense if a trade can happen if either the importer or the exporter are within range of eachother, certainly in the case of a mercantile faction. After all, we assume my merchants actively seek out trading opportunities! After all, I'm getting diplomatically punished for being a mercantile power, why not let me reap the benefits as well?
Now I've come to think of it, how does the cooperation diplomatic option influence all of this? Offcourse, I see some room for more diplomatic options surrounding trade as well. Trade-bans on certain factions as well. I have a feeling that this might be historically correct as well, though somebody else might know more about this.