You can choose to use Fantastical Beauty to improve your wardrobe, or Base 5, or you can choose to integrate them. Working together, at their best, FB5 operates as you see with a Venn diagram. Base 5 can winnow down the recommendations within your Fantastical Beauty type, particularly as concerns scale and silhouette. Base 5 is not a vibe or a style flavor, but a system based strictly on scale and shapes as a way to dress with lines, textures, colors, and prints echoing the scale and shapes of the person. All of the flavor comes from Fantastical Beauty in the form of main type, and optional leanings and subtypes. When you bring the two systems together, you have a more manageable set of wardrobe options.
Base 5 does not translate to other systems that use similar category names, and Base 5 does not line up with certain FB types being most likely based on your B5 type. Every Base 5 type can be found in every Fantastical Beauty type. If you think you're a Classic Round, that tells you absolutely nothing about which Fantastical Beauty type you might be. There are Classic Round Valkyrie and CR Angels and CR Mermaids. You have to come to your type within the approach of each system. Only after can you see where the overlap is in terms of recommendations. If your FB type recommends mixing textures and your B5 type recommends smooth textures, you would seek to use a range of smooth textures in your look.
One of the type pairings people are having the hardest time with is a Romantic Round Valkyrie, so I've done an annotated illustration below to show you how that might look, and I've chosen to highlight Autumn coloring.
Above is a possible casual outfit for an Autumn RR Valkyrie. She is wearing a terracotta pink fitted tee with scoop neck, brown skinny jeans cuffed, a floral-print silk scarf with a honey background/purple flowers/gold accents, and brown lace-up ballet flats. She might also have a fuzzy, textured, cardigan (buttercream or olive) that she lightly belts.
An RR, like any other Base 5 type, could pair with ANY Fantastical Beauty type. If you know you are an RR, that tells you absolutely nothing about your Fantastical Beauty type- it could be any of the 9. What it does tell you, is an idea of scale, preferred silhouettes, and preferred textures.