It appears to me that German is a language whose vocabulary is strongly based on combining a few lexemes with a variety of prefixes, or just yuxtaposing. By contrast, romance languages seem to use far more "unique" roots. I wonder if such a distinction is made when classifying languages in some respect.
I'm no linguist and I can't find a way to ask the correct question or to phrase it so as to find the answer on my own with a Google search.