[quote=@LivingQuietly]
My idea is that the independent Myrese trade networks were confined to the shallow coast and rivers of Mycoria and after the arrival of the Empire all of that infrastructure would have been ceded to them immediately. The fact that they use flat-bottomed shallow boats similar to (scaled up versions of) Chinese Sampan meant their networks were unsuitable for trade outside the province anyway. I'll leave the degree of their involvement in Imperial trade networks up to you at any rate -  the point isn't really that the kingdom is rich, only that its aristocrats and priests are. I'll hopefully be able to show the destitution of its 'impious' common people.
[/quote]

I personally think that the idea is fine at any rate. If it's just a straight class divide between the upper-echelon aristocracy and ecclesiarchy with the rest of greater Myrese society, then I would think that it would likely start to crumble pretty quickly without the backing of the rest of the Mycorian imperial apparatus. I can assume (and correct me if I'm wrong, here) that it's mostly a case of the Gaulletics only caring insofar that they receive their cut (which is by percentile the Lion's Share, but the native Myrese are enamored by their baubles that some don't even realize the extent to which they're actually getting screwed over in this little partnership), and so long as all the dividends are paid out, they largely leave them up to their own devices if they play ball with Mycoria. 

The case of Great Myr as I can envision it is sorta like India or Malaysia under British rule where you saw like gigantic sprawling structures and princely kingdoms of insane amounts of wealth while surrounded by a pretty neglected countryside that was ready to fall apart at first notice. Its geopolitical situation would control a lot of the southbound trade, but because the Myrese ecclesiarchy and aristocracy are so intertwined with Mycoria's merchant class as a whole, they never get the real opportunity to capitalize on the position for themselves - and even if they had, they sure don't possess the military might to thwart a full-fledged Mycorian incursion.