The area bonus has been updated to be fairer to all gangs despite what rank the gang is in the game. Before this change if you were in the bottom gang you would get a extra bonus compared to the gang above you. This was designed to prevent a gang running away with the game, it has helped. However we can see it could be manipulated. So the impact on this has been reduced substantially. It still plays a part.
The biggest issue with a gang running away with the game is other gangs allowing them to do so. It is similar to the gang in last place giving up. If you are a gang leader and you tell your gang not to bover because there is no hope in the first 24 hours well you deserve to be in the bottom gang.