One way to get some more variation and interest out of your rbd simulation is to add secondary fracturing. This can be done in a number of ways but the basic idea is to setup your initial sim with a mixture of hero pieces and supporting pieces (I talk more about that in this video). Then create a second beat to your animation by breaking the pieces down further when they collide with other objects. I prefer to control this manually but you can also set this up to happen procedurally.