>>42610
Well, low German is just a collective name for several languages.
The family tree model is flawed and gives the impression that as we going back in time we meet more and more homogeneous languages - which as we go forward in time get differentiated and branch out into several languages.
But this isn't the case, in the past there were even more tongues and with time, as the interaction between the people, with the ease of travel, communication, with the discovery of printing and telecommunication, the spreading of general education, mandatory schools, and most importantly with the official standardization of the languages became those less and less diverse and uniform. Between the "triumphant" emerging languages the separation became sharp, but within them the differences of the original languages (which they are consisting of) vanished, they turned homogeneous.
As we go back in time we just don't know how they called all those individual languages, so the related ones we hold together into groups and we call them like "Germanic" and such.