It's as i expected. They're trying to build the middle class in these other countries so they have markets to sell to.
The problem with state capitalism is once you succeed in providing housing for the vast majority of your people and unemployment is low, the demand crashes down and the economy hits a slump since nobody is buying, profits aren't coming in so debt can't be paid off.
They're trying to get ahead of this problem by taking the surplus goods over to countries that have weaker economies and a demand for affordable products.
The recipe for building a middle class is simple:
1. Provide cheap alternatives to existing products
2. Enforce anti wage theft laws and raise the standard minimum wage.
3. Raise taxes on corporations making a lot of money so the smaller competition has a chance to grow. They'll slash prices even further to attract more business since the bigger corporations will raise prices to make up for increased taxes.
4. Use the extra tax revenue to create subsidies for schooling, housing, medical care, welfare.
5. Expand the government so more people are employed. Public works programs, schools and hospitals, etc.
Ironically the only places this could happen would be in places with a parliamentary system or one party totalitarian state. The countries that would benefit the most from Chinese investment are ironically those exact types of countries. You need a parliamentary system where one party and its representative can be in charge for a decade or more(e.g. Germany, Russia, Japan, Canada, Australia) or one where a party or council is in charge(UAE, Vietnam, China).
It is entirely possible to develop rapidly without needing another country. It's hard to stay developed though if you don't have an active market. Russians know this lesson well. If you have a market you can sell to when you're developed, however you don't need to worry about that. China is trying to jump start these economies so they can sell to them and export some of their people who can't find work but are educated. Those excess people come in as temporary or permanent immigrants and can potentially gain more influence in government to strengthen ties between the countries. This has actively been happening in the European Union. Britain hated this and hasn't reaped the benefits.