Actually, that is precisely the primary goal, and resources are just a means to an end. Reducing aggression would only make sense if the AI doesn't capture mines or develop its city, but simply attacks until its forces are exhausted (it runs out of starting resources, armies, and heroes). In that case, the game would be reduced to capturing almost empty cities and hunting down weak heroes on whom the AI has scraped together something. But I think that no matter how aggressive the AI is, it should still develop its cities in some way, and therefore ignore mines only in the early stages, while it still has starting resources/an army. I've noticed this in the original ToE as well – it seems that the amount of resources allocated to the AI for its "hero" is sufficient for it to prioritize aggressive development/rush rather than capturing mines. Sometimes, after capturing a city around the third week, the AI surprisingly doesn't capture even the nearest wood and ore mines to its capital – it develops the city with what it has at the beginning and goes on the attack. As you can see, this "problem" is inherent in the original game, not just the modified one.