George Orwell famously observed that "All animals are equal, but some animals are more equal than others."  The same is true of "sovereign" states: some are more sovereign than others. The Holy See has power and influence disproportionate to its size. While there is a legal sense in which the Holy See and the Knights of Malta are equal in the diplomatic world, there is no real sense in which that is true.  The Knights can separate from the Holy See, or be separated from it, but if that happens, it will be the Knights, not the church, who will be diminished. It appears that the religious aspect of the Knights, which binds them to the bishop of Rome, is secondary to their understanding of who they are and aspire to be. They can and probably should be released from their vows in religion in order to pursue their identity and goals in the world.