Forgive me for oft repeating, Trust and Check in some form or another.
If your China manager has any information that you do not have, then you have no verification.
Do not be held captive by your China workers. They are good people but absent accountability, we all do less than we would otherwise.
Oh, and if you have any problem with your Shanghai manager and are not feeling confident you know what is happening under him/her, then give me a call. Shanghai managers have a stronger tendency in that direction than elsewhere though Guangzhou may give them a run for their money.
You can have a good and fully transparent team.