It's more than just academic. The question is not whether aristocracy or plutocracy acts in a fundamentally better or worse way than the other, which you seem to be focused on, but whether they act in a different way from the other, which they very much do. The basis of their power comes from different roots, and because of that, they have different interests, different goals, different avenues of action, different preferences in compromise with wider society. Failing to understand that will result in failing to understand the reasoning for political maneuvering by one or the other.