I would say that the most important time for an INTJ would be either at the founding, or at a moment of crisis when everything needs to be overhauled. During other periods of history, other types could be just as good, if not better, to have as kings. I, personally, think Reagan was an ENFJ, and talk about the ability to bring peoples' spirits back after a really shitty decade-plus -- an INTJ couldn't really pull that one off. I think in bland moments of history, where nothing much is really happening, or at least society is functioning well, and nothing really needs to be overhauled, an ISTJ would actually make a great king. Frankly, if I could vote again, I'd probably add them in there, too. I'm amazed at how little love they're getting. Fucking George Washington and Dwight Eisenhower were ISTJs, and I don't know a single American with anything bad to say about them.