  Superpotentials in ${\cal N}=2$ supersymmetric classical mechanics are no
more than the Hamilton characteristic function of the Hamilton-Jacobi theory
for the associated purely bosonic dynamical system. Modulo a global sign, there
are several superpotentials ruling Hamilton-Jacobi separable supersymmetric
systems, with a number of degrees of freedom greater than one. Here, we explore
how supersymmetry and separability are entangled in the quantum version of this
kind of system. We also show that the planar anisotropic harmonic oscillator
and the two-Newtonian centers of force problem admit two non-equivalent
supersymmetric extensions with different ground states and Yukawa couplings.
