That's pretty solid evidence to support your point, but I personally believe that explanation is flawed. So were kind of left with two options we could debate the difference between a sith and a "true" sith and say she was a sith but did not attain the highest level or we have to accept by that definition neither Maul or Savage are sith. I think most people would agree all three of them are sith. Maul took the same path as Ventress and later on denounced the sith as an organization but still had sith abilities and could activate sith holocrons (I dont understand how you could do that if you're not a sith). Either way cg is wrong somewhere