Say what you will about America's institutional racism, but I have rarely heard an American whine about people not acting American enough (maybe I'm hanging in the wrong circles)
Meanwhile I would hear a lot of complaining about riff raff accumulating around ethnic grocers and the like messing up the "culture " of downtown Nantes.
The integration fallacy is one that is doomed to fail from the outset. The people define an area, not the other way around. Let people do what they want, the free flow of ideas will do the rest.