Initial spatial distribution of the ten clumps in representative simulations of the three different spatial configurations described in Sect. 2.4. The initial positions of the clumps are determined as described in Sect. 4.3. From left to right: Face-on disc, Edge-on disc, and Spherical configurations. Each clump is displayed as a coloured dot. In the first two panels, we plot in grey the trajectory of the circular orbit at which each clump is initialised. This also makes apparent that the orbits of the clumps are co-planar in these two configurations. In the right panel, for each clump we plot the projected distance on the x − y plane as the black solid line, and the z coordinate of the clump as the red dotted line, to show that the clumps are not co-planar.