depend on what you are doing

Most chinese I knew are working in engineering field. They have no need to speak perfect English. They have nothing to worry since all coworkers have all kinds of accents. The priority is actually to improve the writing, not spoken English for them.

I occasionally met Chinese in non-Engineering fields: sales, technical supports, HR, corporate lawyers etc. Those fields need very good spoken English.

Chinese students have learned very good grammar, it is relatively easy to improve their writings in Business English.

If you feel you have anxious about your English level, first check what you really need in your job related to English. Also you have a moment of truth check on yourself to see how far your English level from the job requirements?

Just keep in mind that;
1. Business English is simply;
2. Customer facing jobs need casual talking capability in English, which need you not only learn NCEs, but also read lots of books and watch lots of movies/TV shows.
3. You have no need to understand English in movies. Lost of native speakers may not catch what actors/actresses said either.
4. You donot need to speak like native speakers. Good enough is the key.