I'm not sure why you would say that A isn't orbiting B if the barycenter of the orbit isn't inside B? We normally talk about Jupiter orbiting the Sun or Charon orbiting Pluto despite this not being true. I can see why someone might want that to be the definition for aesthetic reasons but I'm not seeing any evidence that it's the accepted definition. Wikipedia certainly says "near or within" instead of "within" in the most relevant section and I couldn't find anything clearer or contradicting that.