From what I understood it depends on which difficulty you play and what kind of player are you. Myself, I am an empire builder and I am a casual player on monarch. As such I like huge and well developed cities. So for me the overlapping is not that really needed.
BUT - on high difficulties where you try to "snatch" the victory from the AI I guess the overlapping is very useful.
BUT - on high difficulties where you try to "snatch" the victory from the AI I guess the overlapping is very useful.