Gameplay is what matters here.
Military is already heavily restricted, because anywhere you want your units to go, they have to actually walk there. Whereas trade happens instantaneously over any distance
So the mechanics aren't really directly comparable.
Also; Macedon/Greece had no trade with most of Persia or Pakistan. Mongols had no trade with west Asia, Middle East or Eastern Europe. New world civs had no trade contacts with Europe before being conquered. Conquest has outstripped trade on many occasions, in the cases where long-distance wars have been prosecuted.
The Mongols actually did have extensive trade networks. They supported and encouraged trade on a vast scale.
Silk Road Info
The silk road was NOT a "highway" where people just walk to China and just buy something and go home. Silk Road consisted of may minor trade routes and included may diffrent roads. Silk Road connected Asia - Africa - Europe indirectly. It also provided a "Cross Road" of cultural exchange and Cultural diffusion (Sychrotizm). Many goods from Europe will usually take weeks or months to get to China.
Where ever the Silk Road when, it bought great wealth and prosperty because of the goods that were traded on it. Silk Road also was a "Homing Becon" to many dangers. The wealth and gold attracted bandits and thieves. For this reason Traders travelled in huge groups called caravans and was protected by a regional regiment of troops (footsoliders or Calvary).
Europe and Asia NEVER had a direct contact with each other until Venician (Italian) traders like Marco Polo made his way to China. For even this to happen, there needed to be a safe pasage way and a safe trade route. This was accomplished when the Mongols campaigned and took control of over 80% of Asia. They insured safe trade even on the Silk Road. They also encouraged trade and soon bought the Europeans to China which was controlled by the Mongol Dyansty called the Yuan Dynasty.
The Silk Road prospered even more under the Mongol rule and even the people who hated the Monogls benefited from the trade. Many unspeakable riches where given and traded all around Asia and Africa.
http://worldtrade.webs.com/tradenetworks.htm
Along with Western missionaries, traders from the West (particularly from Genoa) began to arrive in the Mongol domains, mostly in Persia and eventually farther east.
The Mongols were quite receptive to this. This attitude, which facilitated contacts with West Asia and Europe, contributed to the beginning of what we could call a "global history," or at least a Eurasian history.
The Mongols always favored trade. Their nomadic way of life caused them to recognize the importance of trade from the very earliest times and, unlike the Chinese, they had a positive attitude toward merchants and commerce.
The Confucian Chinese professed to be disdainful of trade and merchants, whom they perceived to be a parasitical group that did not produce anything and were involved only in the exchange of goods. Mongols altered that attitude and in fact sought to facilitate international trade [also see The Mongols in China: Life for Merchants under Mongol Rule].
In China, for example, the Mongols increased the amount of paper money in circulation and guaranteed the value of that paper money in precious metals. They also built many roads though this was only partly to promote trade these roads were mainly used to facilitate the Mongols' rule over China.
Under Mongol rule, merchants had a higher status than they had in traditional China. During their travels they could rest and secure supplies through a postal-station system that the Mongols had established.
The postal-station system was, of course, originally devised to facilitate the transmission of official mail from one part of the empire to another. Set up approximately every 20 miles along the major trade routes and stocked with supplies of food, horses, and lodging, the stations were an incredible boon to all travelers, whether they were traveling for business or otherwise.
Under the Mongols, merchants also had the benefit of not being faced with confiscatory taxation, as was the case during the rule of the traditional Chinese dynasties.
Support for trade characterized not only Mongol policy in China but their policy throughout their domains. In Persia the Mongols granted higher tax breaks and benefits to traders in an effort to promote commerce. The Mongols even tried to introduce paper money into Persia though this would become merely a failed experiment. Nonetheless, the attempt indicates the desire of the Mongols to provide additional assistance to traders.
To further support trade and commerce, the Mongols established merchant associations, known as Ortogh, specifically to promote caravan trade over long distances.
The Mongols recognized that the caravan trade across Eurasia was extraordinarily expensive for any single merchant. Often there would be as many as 70 to 100 men on each mission, and all had to be fed and paid and provided with supplies (including camels, horses, and so on) over a lengthy period of time.
Quite a number of the caravans simply did not make it, either because of natural disasters of one sort or another or plundering by bandit groups. Travelers, for example, mentioned coming across numerous skeletons, animal and human, on these routes. Because of the expense involved in such a disaster, just one such failed caravan could devastate an individual merchant's holdings.
The Mongol solution to these concerns was the establishment of Ortogh through which merchants could pool their resources to support a single caravan. If a caravan did not make it, no single merchant would be put out of business. The losses would be shared, as would any risks, and of course, profits when the caravans succeeded. The Mongols also provided loans to merchants at relatively low rates of interest, as long as they belonged to an Ortogh.
http://afe.easia.columbia.edu/mongols/history/history4.htm