I am comparing them by how and where the power is invested in each, whereas in communism the power is all in one person's hands, i.E a dictator/dictatorship, opposed to democracy where the power is invested in the people's hands.
I dont think you understand communist theory. Most communist interpretations involve power in the hands of the workers generally through democratic procceses. There is also an anarchy style of communism but non where all the power is in one person's hand. The dictatorships you are refering to were fascist states operating under the name of communism.
I do not care about theoretical or ideological applications. Ideally, Muhammad is a prophet, but realistically he is a pedophile that spread the filth known as Islam. Ideally, everything is supposed to be great, but in application it is not. Communism does not coincide with human nature of advancement and desire for more.
Muhammad was a real person while most attempts at "communism" were initiated by vicious fascists who for the most part weren't even trying to establish communism. If a movement ignores communisms roots, than it ceases being communist and instead becomes its own offshoot.