Physical Anthropology not exactly Linguistic

I've been thinking, physical anthropological migrations don't exactly go with linguistic migrations. For example, Austric speakers are closer linguistically (though only hypothetically) to Indo-Pacific and Australian and the proto-languages would have travelled together before branching off into their respective branches. But, today, most Austric speakers (Kam-Thai, Mon-Khmer, Hmong-Mien, Austronesian), are represented by more "mongoloid" peoples (or their mixtures with "australoid") probably coming from the north through Sino-Tibetan. A mass of Sino-Tibetan speakers, mainly of "mongoloid" stock probably ran through Austric in SE Asia and absorbed themselves into the culture and swamping the "australoid" stock farther south. Don't you think?

 

Take note: again... just hypothetical.