I don't think so. Kim is performing very well, and he seemed busier than Ra in the Mixed match. By the way, those guys always play two matches per day, it is like routine work very day during the match. There are a lot of interviews with players about this, none of them see it as a big problem.
But a little problem may even be enough to swing the balance. Zhang/Wei are the Chinese pair of the future. There'll be many confrontations with Huang/Gao