Hiding Multiple objects

Creating six triggers is best practice. It takes a long time to create the first one, but then you copy the trigger, click the next object, and paste the trigger, all of which takes a few seconds.

Unless you want all six objects to appear and disappear always in unison. In that case, you start copy object B, edit the states of object A, and paste object B into the normal state of object A. Repeat until all objects have been pasted onto the normal state of A, at which time they are one object, and can be controlled with one trigger.

Or, you can cover them with a shape that looks like the background. write a trigger to make the shape disappear, and it will make them look like they are appearing.