The italian mafia maybe present across all boroughs new york, but even they mostly at a street level just stick to certain areas, and most of the crimes they commit are against the people in their own communities, it just who the most accessible people and targets are. Its what every crime group does. Just because the gambinos have a presence in queens does not mean they control the entire queens area, maybe howard beach and other white working to middle class areas. The only activities that might take them out of a certain area work wise is probably the union and construction crimes but even then just because they are behind some building going up in downtown manhattan doesn't mean that all of a sudden that street or block is now mafia turf.