Place random object from group I'm working on a scene with a lot of container ships, where the ship is always the same, but i'd like to have a different arrangement of containers on the ships.

I've modelled the ship and a container. Is there a way to create a group or something similar of different container arrangements and then add instances of the ship that automatically have one of the predefined container arrangements on top of them randomly?
You could use particle systems, there's an option to use a group as particle pool, with pick random option.

Just set up a group with all your predefined container arrangements.

The downside is you wont be able to have each container as a singe object directly, and you have to manually change the seed for each instance.