It turned out the dual swarm was in fact just 1 big swarm.
When I picked them up at 8:30pm they were all in the big box and partly outside.
This is the biggest swarm i've ever come across
I sprayed them with water, and gently brushed them inside.
Even though it was almost dark, quite a few bees were bumping me on my veil.
2 got me (I wasn't wearing a full suit) :-)