For the life of me, I have no idea which hive swarmed, they all look like they did before.
What are the chances they are from somewhere other than your hives?
Nothing really too do as you said you have already checked. Signs to look for: Does everthing have space and room for queen to lay? Spot eggs in all hives? See any other queen cells? See any open queen cells? Any hives with weaker numbers and just capped brood not brood in all stages? Sound like you are in a flow so should have brood of all stages. Any back filling of brood nest?
You said they all look the same as before.