Hi folks!
This is an awsome project you're persuing here! I'm back at modding now after a longer absence (btw: @all sorry for that, but i hardly had a choice) and maybe i can support you a bit here.
The first thing coming to my mind is that the Heaðobards are as good as identified as remainging Langobards who are about to get assimilated into the Saxon society as an ethnical minority.
The actual Langobards by this time have allready arrived in Pannonia where they subjugated the Gepids and defeated the Heruls, causing their exodus to Scandinavia.
Those name crations of yours, DV, are some nice ideas, but i think this can be researched more properly. The protogermanic "iz" and "az" endings allready changed into the Proto-Old-Norse "ir" and "ar" which was taking place within the scope of the upcoming Vendel-Culture and probably casued by the arrival of the Heruls (much rather "Erilar" btw! ) on Skandza.
I have relevant material about this, if you will, but alas, it's in German. Will see if i ca translate parts of it.
cheers!