Marxism predicted a temporary dictatorship of the proletariat during the proletariat revolution. Marxist-Leninism took the temporary dictatorship prediction and ran with it, establishing a permanent dictatorship of the communist party, which Lenin called the Vanguard Party.
There are Marxists that disagree with the idea of the Leninists’ Vanguard Party and authoritarianism. Tankies, on the other hand, are the communists that support this idea of a permanent communist dictatorship and its authoritarianism, at least in a nutshell.
So I would say that most ML Commies are technically ‘tankies’, but not all commies are ML. A lot of commies are just M.