I'd taken bees from my strong hive where the Queens had been raised and put them into the mating hives with one of the Queens in each, then moved them, as you say, the 3 miles.
For some reason, presumably because they all knew each other, the ones from the centre mating box moved in either side. Even though the boxes were separated by a few feet, lesson learned though separate more and face the mating hives in different directions.