No, containers are not similar to families at all!
You can combine different object into a container, for example sprite+text+particles.
Container holds instances of these objects, only 1 instance of each object per container.
For example, you can have your main Spaceship sprite, Thruster sprite, TrusterFlame particles, MainWeapon sprite, HealthBar 9patch. Add all these objects into one container.
When you create a new Spaceship in runtime, all instances of other objects from the container (Thruster, MainWeapon etc.) will be created automatically. You will only need to position them properly and pin if needed.
If you create 10 ships like that, you'll basically have 10 containers.
(If you create Spaceships and all other sprites from the container manually in editor, you need to do be careful to add them in order. Otherwise you might end up with different objects attached to wrong spacehips.)
When you destroy a Spaceship, all instances of other objects from the container will be destroyed automatically.
If you pick one object instance in an event, you can reference all other objects in the same event. For example:
Bullet On collision with SpaceShip
-----------------> SpaceShip Subtract 1 from health
-----------------> HealthBar set width to SpaceShip.health
(notice you don't need to pick this spaceship's HealthBar , it's picked automatically)