“More Semitic inheritance” is a claim not significantly borne out. DNA indicates less than one-half of one percent intermarriage between Europeans and Jews in Europe over 50 generations! I suppose that’s more than .005% of European intermarriage with Jews not living in Europe, but really?
You may be correct — I have no statistics at all on this, just based on the looks — most Yemeni Jews look like Arabs or Kuwaitis. Many American or European Jews even have blonde hair. That’s why I would guess that they’d have more European blood — but of course, this is not a scientific look, so I may be wrong