Zhang Hao's mid-range shot basics are nearly perfect. At Zhang Hao's level, it's no longer a matter of others guiding him to become more accurate. He's reached the point where team training or actual games are needed to find possibilities for improvement. Perhaps, at this stage, there's no room for progress.
A skill doesn't necessarily improve endlessly through practice. Many people reach their own limits and stop improving, and most people's limits aren't very high.
