From what I can see... although China did not receive (or with very very minimal help) from any other nations in the development of their aircrafts in recent years, they still not yet reach a truely indigenious development yet. Until the Chinese could field their own engines even in their prototypes and first flight then, they have reach that stage. At present moment, although we are seeing lots of engines development projects that had reach very advance stages, I am not seeing these engines in the aircrafts. Even Y-20 are flying with the Russian engines, although the Chinese ones are in pipeline.
However, using foreign components doesn't necessary means they are receiving technical assistance from that foreign nation, because Chinese bought these components from the foreign nation fair and square.
I agree with your point. Chinese simply do not even need consultant from Russian regarding D-30K engine. They have many years of experience overhauling their IL-76 fleet. They even install these engines on H-6K. The only thing they ever needs is to buy the engine from Russian for temporary uses.