Vietnamese, Japanese and Korean shared common O2b mtDNA. Its mean: in the past Vietnamese, Japanese and Korean tribes were living nearby each to others in mainland China, before the time when Japanese went to East China sea, Korean went to North East Asia to Korean peninsula.
Conclusion: legends about the Hung Kings, Van Lang and Xich Quy country 東夾南海,西抵巴蜀,北至洞庭湖,南至狐猻精國 in middle mainland òf China ís a truth.
How many times I have to say this haplogroups predate the existence of some language families and ethnicities,it is pointless to determine if an haplogroup strictly comes from one ethnicity to another as population bottlenecks can occur.
The haplogroups O 002611,O M134 and O M117 are the most common O3 in Han Chinese,so are Vietnamese/Koreans/Japanese with these haplogroups actually Chinese?
No they weren't the Jomon from recently studies show they are an early Siberian population that moved to Japan while the Yayoi were mainly from Korea while some are from China.
Later Korean kingdoms such as Baekje had kinship ties with the Yamato state there were plenty of immigrants that came from ancient Korea and China.
As for Koreans there was the indigenous Sam Han and migrant Ye Maek later on some Khitans and Jurchens assimlated into Korean society not to mention that Han dynasty established some commanderies there .
In my opinion the Vietnamese are the most mixed out of the 3,from what I read the original inhabitants of Vietnam were Australoids while incoming groups of Mongoloids(Austroasiatic and Tai Kadai speakers?) either exterminated or assimilated them.
Also the Chinese ruled Vietnam for quite some time and many Chinese refugees also went to Vietnam in times of turmoil such as the Ming loyalists.
With the southward expansion of Vietnam Khmers and Chams were absorbed.
Now you are claiming that Japanese and Koreans were part of Van Lang,Vietnamese nationalists are absolutely hilarious!
Why is O2b* and O2b1 found it negligible or nonexistent amounts in Han Chinese then?
Your own history book Kham dinh Viet su Thong giam cuong muc expresses doubt on the accuracy of Dai Viet su ky Toan Thu and linh nam chich quai.