Mary was really a clueless dope very often. She should have allowed Knox to think he had converted her and nominally become a Protestant. If Paris was worth a mass than Edinburgh was worth a baptism. Knox as an ally and confederate would have been a powerful pillar of support. Over the long haul, even if Mary had to fly the coop from Scotland as a Princess converted to the reforming faith she would have been a guest not a potential focus of sedition in England. In passing, have there have been any more complete set of fools in history than the Catholic gentry who involved themselves in such idiocies as the Babington plot.
James was a queer, Charles was an idiot, his son was also an idiot. James had to get out of dodge because he was an idiot.
I guess the only two might have been Mary-William and Mary, and last Ann-who was also weird.
I can only count..up to the Hanoverian's, a few monarchs who were worth anything. Edward the 3rd comes to mind.