Sadly the data from my city does not include everything (even their own GIS system is missing heaps of stuff or even has wrong or ambigious data) so importing f

Sadly the data from my city does not include everything (even their own GIS system is missing heaps of stuff or even has wrong or ambigious data) so importing from the city still leaves quite a lot of gaps that has to be filled in other ways. One example is my home city. My city's GIS data has no idea of houses just sections. So you may have a property that has been divided up into several sub sections with their own houses. In many cases the city data only has data for the parent property and assigns all the relevant data e.g. house numbers to one location. This results in one large property having multiple street numbers assigned to one fixed location (usually in the middle of the whole lot). I've had to fix this (by splitting up the street numbers so they are each correctly mapped to each house) quite a few times in OSM because of bad city data. This issue is also present in the city's own GIS map so that's how I know it's the city at fault—it's actually not always possible to determine the correct house number using their own data. I can see why may actually be more efficient to just skip the city data and get better data via other means.