I think you'll find that people who use software that has mapping, make data fit in differant ways
I.E. A person born in Austrasia in say the year 600 AD
if you put it into my program as the Old Kingdom of Austrasia the program will alow it but of course when mapping it will map it as Australia (wromg side of the world)
To get it to map it right (or mostly right), you have to enter it as The Old Kingdom of Austrasia, Belgum. Although Belgum may not have been the actual area, the software will map it more-or-less in the middle of That Kingdom.
The same kind of thing happens with GB (the software places it in Palistine) and many other old countries (many of the old soviet countries do even odder things)
Untill the writers of Genealogy software start to add in the old kingdoms etc, people will continue to "correct" the software by inputing that incorectly.
To work with the softwre for London, something like "London, London, England, GB, UK would have to be input.
The only thing I can suggest is if you find one, Correct it on Geni, but be prepared for someone who uploads from another program to get it wrong and find out what software they're using and ask then to write thier software companies to help get historical maps into wide use in Genealogy.