There was a 2nd fighter that followed the EP-3 to Hainan. Contrary to what ist pilot said, he could have flown to Vietnam instead.
In 1979 war there, China didn't use its AF at all. If the USSR didn't issue a threat, the PLA was likely to try yo capture Hanoi. They have plenty of cannon fodder to do it. Now, their SOF hone their skills:
Their Marines trained in Xinjiang & Yunnan:
Chinese Troops Arrive in Syria to Fight Uyghur Rebels
As stated by the current US Pacific Command chief Admiral Harry Harris: “China is now capable of controlling the South China Sea in all scenarios short of war with the United States.”
Their guerillas, mostly peasants, learned to fight well in a civil war & kicked the Nationalist army who earlier fought the Japanese to Taiwan in 1949. "In the 20th century, the Chinese Communist leader Mao Zedong partially credited his 1949 victory over Chiang Kai-shek and the Kuomintang to The Art of War. The work strongly influenced Mao's writings about guerrilla warfare, which further influenced communist insurgencies around the world. ..Ho Chi Minh translated the work for his Vietnamese officers to study. His general Vo Nguyen Giap, the strategist behind victories over French and American forces in Vietnam, was likewise an avid student and practitioner of Sun Tzu's ideas." https://en.wikipedia.org/wiki/Sun_Tzu
The PLA saved NK from being defeated & occupied by the USA. Their regular soldiers & marines also do physical exercises & hand to hand combat training as a matter of routine. So, it's very close to real combat. Even w/o recent combat experience, they can learn quickly.