you're right
Helmsman, correct to Indonesia-to-Cambodia-to-Siam-to-Bangladesh-to
If you're already in Indonesia, wouldn't it be easier to go directly through the Malakka straight instead of going back north to Cambodia, then Siam, and then back south to Malakka/Indonesia?
Nevertheless, I repeatedly read that the Chinese were "less expansionist". Why is that? Han Chinese gradually colonized the South. Whereas already the first Emperor held Southern Chinese territories, it required centuries for the Han to colonize them. As far as I know, this gigantic movement of peoples wasn't finished under the Song, neither under the Yuan. Peripheric provinces such like Guangxi or Yunnan would probably come even later. And then colonialization of Manchuria started.
So actually, the Chinese were very expansionistic. It's only that natural borders (desert, mountains, sea) limited expansion of their state. At the same time, state frontiers were generally wider than cultural/population frontiers, which made inner colonialization possible. For centuries, any population surplus found its space in the South - or died in droughts, floods or invasions. The Europeans on the other side required space for their population surplus. That's the main reason for European settlement.
Considering trade colonies of the Europeans, I think we actually saw the beginnings of such under Cheng He and the Chinese tributaries. If the Chinese had stayed and fortified, we'd probably had seen similar colonies in the reest of Asia like the Europeans established later. Outright conquest of American civilization is probably more a European thing. Christian missionary being an important part as well as autonomous leaders such as Cortez and Pizarro - not a specialty of the rather bureaucratic Chinese.