For starters, overcapacity got nothing to do with export-to-GDP ratio. It's about using subsidies to manufacture goods to an extent that outstrips domestic demand, flooding the global markets with the excess production.
As you well know, consumption and import as share of GDP is much larger in EU than in China. So just comparing the exports doesn't give the full picture.
So why is this different from production of German cars or French wines? First, the amount of subsidies pumped in to Chinese factories are far larger than anything we have seen in Europe.
Second, China's government has an outspoken industrial policy to dominate global production in several high tech areas which are more important to nationals security than gasoline cars or wine. Success in doing so creates a harmful dependence on a dictatorship.
Third, with the help of state subsidies China already managed to dominate the world in solar power, knocking out European companies in the process. Complacency will give us similar results in other important areas.
Let me know if you have any more questions, or read my report on this topic for the Swedish think-tank EPHI:
ephi.se/en/publikationer/pub…