My parents house was a traditional home that had the typical Japanese garden in the back with various different trees, plants and many seasonal flowers. I grew up playing around our Japanese black pine, Japanese plum, loquat (Eriobotrya japonica) and pomegranate trees, all the while enjoying the azaleas, camellias and many other flowers that my father nurtured with so much love and dedication. I also remember that we had flowers that were originally introduced in Japan from foreign countries, such as Amaryllis (Belladonna Lily), roses, daisies, and dahlias. So while our garden was very Japanese in style, I can now see how it was more like a display of universal nature.
To get a beautiful flower design or an arrangement, you don't need to show all of these three. The most important here is that your design has ornamental flowers; you will still get a terrific and an artistic flower arrangement.