But does it matter? Does it actually matter in play whether the ogre is a clock or is a bag of hit points? I don't think it does, except insofar the bag of hit points has a more narrowly defined set of applicable mechanically discrete PC abities that can be leveraged. Which really just shrinks the game. But otherwise, it's still some re that says some number of appropriately high dice rolls overcome the obstacle. So from that perspective
@overgeeked is right: the (specific) rules don't actually matter.