At the moment, posting Thompson may be a better option: Cousins' mobility advantage is enabling him to get offensive rebounds over Hibbert, whereas Thompson doesn't have the strength advantage over West that he normally has, so he's not been as successful as he normally is keeping his man off the glass.
Obviously a strategy of running the offense through Thompson is insane on the face of it, but it's not as if keeping Cousins from having to make awkward failed challenges against Hibbert is totally without merit.