Hi there, several of these buildings should be divided much more than they are.

Rapid Editor is useful more for standalone houses than it is for series of plexes. If you'd like to use it, some of the areas up on the East end of the Island or in Laval might be good places to start, since they have many standalone buildings.

In addition, please use the offset of 0.6,-1.54 for the Bing imagery in the region of Montreal, as specified on the wiki: https://wiki.openstreetmap.org/wiki/Montr%C3%A9al