Custom sequence of 3D object appearances

To create an appearance for one task link with many 3D objects to appear in custom sequence. For example, I have foundations, and in my Gantt chart they are one task, but I want to show to my supervisors that they would do them in sequence. (Sequence attached) I don't want to break down the structure of my Gantt chart to because it breaks down of all activities is too demanding at this moment (lack of information).