The ease of mono-cultural (Han Chinese) coordinated societal and economic change - are you referring to the Great Leap Forward and the Cultural Revolution ? You are right, unquestioned fealty to a President for Life would never work in a diverse, multicultural country like India.
Another way of looking at things is that the advantage of social coordination that comes from a huge monoculture is strong enough to vastly outperform the fractured diversity of India despite the incredible unforced errors you mentioned.
One cannot cherry pick the economic growth in last 35-40 years of Chinese history, completely ignore the decades before that, and then proclaim the advantage of mono-culture.
The Cultural Revolution [1] "Millions of people were persecuted or suffered public humiliation, imprisonment, torture, hard labor, seizure of property, and sometimes execution or harassment into suicide. Many urban intellectual youths were sent to the countryside in the Down to the Countryside Movement. Red Guards destroyed historical relics and artifacts or ransacked cultural and religious sites. " [1] https://en.wikipedia.org/wiki/Cultural_Revolution
A single party system led by a dictator for life was the cause of the errors in the past and is the situation in the present. There is a problem with mono-culture.
