Racial distinctions between East Asians

Hello. As a Frenchman can most likely discover a Swedish guy within a group of Greeks, can a well-traveled Japanese person easily distinguish between a Northern Chinese, a Southern Chinese, a Manchurian, a Mongolian, a Korean and a compatriot of himself? If that, could anyone enumerate some particular physical features of any "racial group" of those? In my personal experience devoid of any travel to Japan and based on Japanese movies among other sources, I find for instance that a prominent nose is not very rare with Japanese people, or at least it is considered an element of beauty being those people specially selected in the media world. I have also found Japanese people with the characteristic "ukiyo-e facial outline" (long, rectilinear and tighter face).

I was born in Northeast China. Before I went to work in Canton, I thought all of the southern Chinese were same. But when I got here, I know I was wrong. There are 3 totally different ethnic groups in Canton. And they speak different languages, living a different life. Now, I can easily distinguish them from each other.
Once I walked in a campus, a Vietname girl asked me if I was a Korean. Before she spoke English, I only thought the girl was a Cantonese. And I also knew, that I was totally different with a Korean. And Korean can distinguish me as some Chinese easily.
In Canton, I can easily tell who are Korean, because they yell all the way around. But I'v never found a Japanese on street, because they never show off and to me, they look just like Cantonese.
BTW I can only tell an American from European, but some guy told me you can never think all the Americans are same. Because America is a huge country. And a German told me French hate English most, that's why they always sell weapons to China.

physical features....
I can say some in my opinion.
Mongolians are very man, and most of the times fat. Their symbol is small eyes like some blade. When you travel to some Mongolian's camp, remember, never put your bag on the bed. Because you should sleep on that bed even between owner's daughters.
Northeast Chinese may be the highest among the whole east asians, because the local weather is cold and some of them only eat beef and sheep most of the times.
Korean have big nose and most of the time they can be mistaken with Northeast Chinese. But to me, Korean's eyes are small and have biger head, shorter legs. All of my korean classmates since primary school, are always having a nick name like big head or some stuff like that. Korean women have good body shape and good at dance, prefering eating dogs and good salt vegetables. But I can only admire them, dare not to marry them. Because most of the korean do facelifting. This is scary.
Manchurian are totally Chinese now, they blend in Han ppl. To me, Manchurian are always rich, baby fat, small eyes and gentle.
Traditional han ppl live in the middle of China, like Hangzhou, yangzhou and Nanking. They have very good talent of debate. And many scholars come from this region. They are very clever, but too gentle.
Ppl live in Canton, Yunan, Guangxi have a little blood of Malay, so they have round eyes, dark skins. But they are very good at business.
Taiwan, Fukien and Japanese, to me, they just look the same. When you donot understand Fukienese and Japanese, you may think if they are speaking the same . And when I come to southern China, I consider that Fukien and Japanese beauties are more attractive to me. Meanwhile, my cantonese friend always tell me they are fascinated with by girls from my hometown.

Thank you very much for your cultural and anatomical explanations