Yes, very interesting. The sedevacantists (not all of them, however, but generally) claim that if we believe that the Franics is the pope, then we cannot resist him. The ralliers believe the same - that we (the SSPX and Resistance) must be in full communion with the Pope and Rome. It's basically the same principle.
While you oversimplify the principle (it's not about resistance but about the indefectibility of the Church), this is in fact correct. Conservative Novus Ordites and Sedevacantists adhere to the same Major, the eminently Catholic principle that legitimate Catholic Magisterium and the Public Worship of the Church cannot become corrupt. This principle has only been taught by every Pope, Father, Doctor, and theologian throughout the entire history of the Catholic Church ... and has been denied only by Old Catholics, Eastern Orthodox, and Protestants prior to the creation of mainstream "R&R" theology.
By R&R I refer to some modern types who claim falsely to be heirs of Archbishop Lefebvre. Archbishop Lefebvre himself upheld the principle of the Major that the Papacy is protected by the Holy Spirit from corrupting the Church. He simply questioned the Minor in terms of how this could have come about. So those who try to defend their Old Catholic position as being that of Lefebvre are slandering him.