See my answer here - if one puts all the names into the Proper (not the First name field) when searching one gets less hits and therefore more accuracy. The reason - when the first name field has more than one names in it, the results will also include the identical name even if it has second, third or fourth position.
This a major cause of people not finding profiles on "First name" [sic!] in combination with LNAB, because only the first 100 gets shown, when there might be thouusands.
Maria Susanna Sussara
Sussara Maria Susanna
Susanna Sussara Maria
Maria Sussara Susanna
Susanna Maria Sussara
Sussara Susanna Maria
This is one of the major causes of duplication.
The other is it is clear to me (not US born but with the same German / Dutch heritage) that even if that field is called "middle" name, it is meant for all the other second and third names.
That I where I always put it. The second and third names, not in the "Proper" name field because they were not meant to be put there.
So when I search on First Name (Johann) in combination with LNAB, will result in much less results (more accurate) than in combination with both names (Johann Heinrich) in the same field ...
That is what I'm trying to make clear, it is not about semantics (which culture calls what part of the name how) but about the way searches are performed by people and search functionalities ...