The parties can engage expert assistants(专家辅助人) — or "China’s expert witness" as dubbed by some people — to help them express opinions on professional issues. Although the relevant rules of expert assistant need to be improved, the parties can give it a try to strengthen the persuasion of their opinions.
The expert opinion is professional opinions provided by a neutral judicial expertise institution to the court on some factual issues of a case. As a type of statutory evidence, it plays an important role in China's civil litigation.
Though China's evidence presentation order system differs from the evidence discovery and disclosure in some ways, for those who wish to obtain the key evidence controlled by the other party, it is worth to have a try.