I'm a bit astonished to see you of all people, Rex, advocating a solution where Dutch is subsumed under (Low) "German languages" - I must have misunderstood something about the opinions you hold. -) Anyway, not that I'd object in principle. For the record, here's a very useful passage from de:Niederdeutsche Sprachen, which I think might serve as a useful point of reference: 

 :"Der Begriff „Niederdeutsch“ wird heutzutage recht unterschiedlich verwendet und kann in der zeitgenössischen Literatur verschiedenen Konzepten entsprechen. Der belgische Sprachwissenschaftler Goossens zählt bis zu zehn verschiedene Bedeutungen. 
 :Die Unterschiede beziehen sich hauptsächlich auf die räumliche Verbreitung, vor allem die Ost-West-Ausdehnung: So beziehen einige Wissenschaftler den Begriff „Niederdeutsch“ nur auf die Varietäten Norddeutschlands, andere beziehen ihn auf Norddeutschland und den Nordosten der Niederlande (Niederdeutsch gleichbedeutend mit Niedersächsisch), noch andere auf Norddeutschland und den gesamten niederländischen Sprachraum (Niederdeutsch im weiteren bzw. historischen Sinne)." 
 :My translation: 
 :"The term "Low German" is used in different senses today [...] Some scholars use the term "Low German" to refer only to the varieties of northern Germany; others to northern Germany and the north-eastern parts of the Netherlands (in which case it becomes synonymous with "Low Saxon"), yet others to northern Germany and the whole of the Dutch-speaking area (Low German in the wider or historical sense). 
 Personally, I was not actually very familiar with this last (wide) concept, so I'd probably be a bit astonished as a reader to find it taking precedence in the article titling. Also, I don't think I've ever seen the term "Niederdeutsche Sprachen" (as opposed to just "Niederdeutsch") in German usage, outside Wikipedia. And finally, having two different articles under "Low German" (narrow sense) and "Low German languages" (wide sense) seems a bit confusing to me. So, perhaps an alternative solution: 
 *Move Low German to Low Saxon as per Rex; 
 *Leave Low Saxon-Low Franconian languages where it is now, or move it back to Low Germanic languages, still treating LS+LF, but with a disambig passage in the lead that makes clear there's also the usage where "Low Germanic" includes also English etc.; 
 *Turn Low German into a disambig page pointing to Low Saxon and Low Germanic languages. 
 (Note that the last step will require a lot of link checking and disambig correction in other articles.)