I state that this feeds 4. You may be able to feed 6!
You can switch out any vegetable with something else in season or to your liking. Remember however, that the type of veggie you choose will affect cooking time. For instance, sweet potatoes will take a lot longer than cauliflower. Adjust when you add certain veggies so that they are cooked before you add the kale and cabbage etc. You don't want to overcook any vegetable in this soup.