As in Fig. 11, but evaluating the dependence of our results on the definitions of merger mass ratio and merger time. We consider the mass ratio defined at the time of the maximum past mass of the secondary (fiducial; top panel), versus at the time of 0.5r_500c crossing (bottom panel). We also contrast definitions of the actual merger time: when the secondary (incoming) halo crosses 0.5r_500c of the primary (fiducial; solid lines), versus the crossing of r_500c (dashed lines) or r_200c (dotted lines).