Hang on. City level officials play an incredibly important role in China. While Nanjing is not in the same tier as Shanghai, Beijing, or Shenzhen, it is in the tier just below them. It is the provincial capital of one of China's most important provinces -- GDP similar to Texas. Many large Chinese companies are often tied to specific cities -- they get grants and subsidies via the city they are located in.

This guy did it over 30 years so it is feasible.

Scapegoat isn't the right term but I think it is very possible he is being executed to essentially send a message. I think your bigger point that there are way more corrupt officials than just this guy involved seems very plausible.