Marmalady's recipe looks delicious, but isn't traditional Miso Soup, which is based on the less is more principle. There is a Japanese name for her soup, but I don't have the book in front of me to provide it at the moment. True Miso Soup doesn't have all those vegetables, nor does it have any noodles. Not knocking her recipe at all - in fact, I've copied it to try it - but it's not Miso Soup.
I make Miso Soup all the time. In fact, instant Dashi-no-moto granules are a necessary staple in my pantry. I always have them on hand.
My favorite recipe, which serves 2-4 depending on what you're serving with it, is just bringing about 3 cups of water to a boil & adding a tablespoon or two of the granules. Stir to dissolve & then add 3 tablespoons (or to taste) of miso paste (any type - although I'm fond of the yellow types myself). After all is combined, taste the broth to see if you need to add more of either ingredient.. Then add one block of firm tofu, cut into small cubes & one or two scallions, finely chopped & serve.
Some recipes also garnish the soup with a sprig or 2 of edible green seaweeds (there are a number of varieties), so if you have these available to you, by all means go to it.