I was just in Hamburg visiting Dani. Interesting city and the Maritime Museum is worth seeing. Also ship SS Cap San Diego. The Bismarck dock is clearly visible from the other side of the river but they will not let you into the shipyard no matter how much experience you might have with shipyards and ships as Dani and I found out.
Anyway, I think what Dani is saying is that while official personnel transfers are common in war, family moves at that time in Germany were different due to many economic and social reasons. Uprooting a family, especially in Germany during the war, might have been more common later due to bombings and shrinking frontlines (from the perspective of Germany). While Germany is somewhat considered an industrialized country during that war due to its prodigious military output, it was still primarily an agrarian country nevertheless. So to move a farmer's family someplace else, or a shopkeeper, or a mine worker, a good reason needed to be established.
All that discussion aside, and others should comment, what Dani is trying to point out is that for your purposes, anything you can get from the family in the way of provenance helps when you purchase artifacts from this era. Speculating that a boy might have moved here and there is one thing, if you can get documentation in the form of paperwork or even an oral narrative signed by the dealer or the family, that would be great. I have tried this many times with families, but it can be hard.
However, if you keep at it, who knows what kind of file you will be able to amass and I have seen collectors given large amounts of paperwork and artifacts for free from families that thought the collector would take care of those items. I have even had old Waffen SS men freely discuss their wartime activities once they settled down and determined that the motives for the discussion were out of an interest in them personally and not a critical assessment of their record. I do not collect anything but MHJ and KM war badges, so my discussions with German veterans have been by accidental introductions for the most part.
So I think that is all Dani is saying. Get the information, build the file, do the research. After all, this forum is called the HJ Research Forum and for me, research is the best part of the hobby.
John