Is it just a mere coincidence four Far East Oriental leaders (Mao, Qin, Tokugawa, Wang Kon) are given the protective trait in the Warlord expansion? I don't think so.
Firaxis gives them the protective trait most likely because they perceive these leaders, or more likely, the oriental people these leaders represent, as defenders and isolationists.
If you consider the leaders themselves, OK, Tokugawa adopted isolationist policy when he got old. However, Qin should not have got the protective trait. Qin built the Great Wall does not mean he's a defender or isolationist. In fact, he's the classic example of what an imperialist means - an empire builder. Mao did not befriend Americans does not mean he was an isolationist. It's just his friends were Russians, North Koreans and Vietnameses. He was a philosopher, and he really tried to implement communism, so why take away his philosophy and organized traits? About, Wang Kon, he wasn't even the greatest leader in Korean history. I don't know why he was picked.
In terms of the civs they represent, ancient Chinese were quite open-minded till mid-Ming. Tell me why there was a Silk Road (which I believe it should be made a Great wonder) to start with? Ancient Chinese (and even Chinese today) were about imperialism, high productivity, powerful economy (study showed that Chinese generated 1/4 to 1/3 of total world output till early 1800's), sophisticated bureacratic system. Giving both the ancient and modern time Chinese leaders protective trait is just not right. Except in the Edo period, Japanese were not isolationists. And where is the financial prowness of the Japanese? Their spirituality aspect? Their highly organized and stratified society?
Tokugawa was given the aggressive trait probably because Japanese have attacked the US before. Mongols leaders were imperialistic/aggressive because they attacked the Europeans. Everything is based on the EuroAmerican perspective.
When is Firaxis going to stop this crxp?