If I am not mistaken their age diffences should be quite huge. Wu San Tong was one of Yi Deng's students. All Yi Deng's students should be about 10+ years older than Guo Jing and Huang Rong. Since Li Mo Chou was about the same age as Lu and she was Younger than Huang Rong, the age diffences between Wu and Lu's wife should be more than 10 years.