We report simple model treatments and quasiclassical trajectory calculations dealing with collisional relaxation and alignment of molecular rotation in atom-diatom collisions. Since these models and trajectories involve single collisions, our results do not pertain directly to alignment due to supersonic expansions but nonetheless serve to elucidate some major aspects that need to be taken into account for mechanistic interpretations. By comparing alignments found for different potential functions (pairwise additive Lennard-Jones, purely repulsive inverse power, and hard ellipsoid) over a wide range of collision energies and impact parameters, we map out three qualitatively distinct regimes. These include "near-Gorter" and "anti-Gorter" regimes, dominant for direct collisions at small and large impact parameters, respectively, and "pseudo-Gorter" behavior found typically for low energy, large impact parameter collisions subject to soft, sticky potentials.