If you look through the literature it seems that drones fly 1 to 7 miles to Drone Congregating Areas (DCA)
If the drones only fly a km from the hive, how do DCA's form in random areas in relation to hive locations?
In reverse to not mating with your own drones, why would you not won't to have plenty of drones to flood the DCA with drones of quality, rather than take "pot luck" if the local drones are of dubious quality.
There are some of hives that i wish would not lay drones a I would not want (if possible, probably not) my new quality young queens mating with some of these drones.
For this reason most of our genetic improvement has been by using mated queens.