The rotational and torsional dynamics of the prototypical floppy indole(H2O) molecular cluster was theoretically and computationally analyzed. The time-dependent Schrodinger equation was solved for a reduced-dimensionality description of the cluster, taking into account overall rotations and the internal rotation of the water moiety. Based on our results, it became clear that the coupling between the internal and the overall rotations is small, and that for typical field strengths in alignment and mixed-field-orientation experiments the rigid-rotor approximation can be employed to describe the investigated dynamics. Furthermore, the parameter space over which this is valid and its boundaries where the coupling of the internal and overall rotation can no longer be neglected were explored.