It is quite common to refer to varying levels of a belief with qualifying names.<quoted text>
So then all theistic philosophies can be lumped into one. Those that believe in Quetzalcoatl or Shiva or Satan or Allah or Jehovah or Baal or Thor or ??? can all be considered the same? Really?
Buddhism is an atheistic philosophy, as is Humanism.
Philosophy can be used in broad as well as narrow strokes to define differing belief systems.