If they are shaken from hives in the same apiary, half of them or more will return to their original hive. If not, yes, they do drift to the better queens. But it really doesn't seem to matter that much how close they are. They will drift. The main way to limit this is to install them just before dark so they have less time to drift before they settle down for the night. If the weather isn't hot, you could block the entrances with some grass until after dark.