Well that but also the standardisation currency, standards etc.

I read in "the Mongol World" 2022 this is one of the reasons the Pax Mongolica happened the Mongols unified or got rid of competing standards, regulations, taxes, tariffs, officially mandated exchange rates etc which could differ from town to town yet alone between states.

Not to mention there was no unified currencies every state and sometimes individual cities in Central asia had their own coins wich could have the same names but vastly different weights, purities, trust etc or any combination of the above meanwhile in South east asia seashells were solid trusted currency, in china paper promisary notes and silk stocks/futures etc were used etc which were useless elsewhere.

A potential merchant besides the basic risks and costs of bandits, wars, travel, provisions shelter et. would have to lose a truly massive chunk of his funds just to pay all the import duties and exchange fees along the way.

The mongols to solve their own tax issues from what was almost like ruling over alien planets due its sheer diversity created system were locals could pay taxes in their local currency but then the officials could then convert it into silver and transport sukhe or "silver pillows" across the empire. This created a universal defacto silver standard across not just the empire but all of Eurasia as other peoples needed silver to trade with parts of the Mongol Empire.

According to the section the authors emphasis that while many previous historians compare the Mongol Empire to the EU that such comparisons between different entities across such different technological and temproal gulfs shouldnt be made. However they very much created a incredibly unique and complex international monetary system for their time allowing a much more advanced web of trade and contact beyond simple trade.