While some people like to have a special holder dedicated to each nib type that they use, this is absolutely not necessary. Fun? Maybe. Expensive? Quite possibly. Overboard? That would depend on if you are the type that could lead a group titled "Art Supply Hoarders Unite." Because, let's admit it, there are plenty of us out there!
All joking aside, you can certainly buy multiple holders and dedicate them each to your favorite nib, but you really don't need to. Calligraphy pen flanges are meant to be used with various sized nibs. Some may take an extra shove, some may require a minor flange adjustment (see other post on that), but they will work. Although I won't tattle on you if it's your excuse for treating yourself to another gorgeous holder. :)