Marriage in VN. Single certificate wrong nationality.

The Vietnamese Marriage Cerificate has two separate lines for Nationality and Citizenship.  So my dân tộc is listed as Caocasian [sic] and my quốc tịch is Hoa Kỳ.  My wife's designations are Kinh and Viêt Nam.  These terms translate in Google as nation and nationality respectively, but the license seems to use them as ethnic group (or race,) and citizenship.  I tend to question the Google translation as it does not reverse translate.

Obviously the terms nationality, citizenship and race can be confusing in English and when it comes to translating such words things get worse.   Nationality can be interchangeable with either citizenship or race but it means an entirely different thing in either context.  (I won't even go into the argument that in the Linnaean system all humans are in one race and what we call race are called variants in other animals.)  The license seems to use the term dân tộc for what most English speakers would call race.   Perhaps the Finnish government sees it the same way.  Is the document being translated directly Finnish>Vietnamese or Finnish>English>Vietnamese?  A lot could be lost along the way.  As you seem to indicate that your brother is already in Vietnam, why not just suggest that he go in for the license and see how it works out?  As you said he has a passport to indicate citizenship and to tie in the single certificate.