Sometimes.
When I plant minis I alway buy three at a time just so they have some impact in the garden. There are other cases, too. There's a place in my garden where two paths cross. I intend one day to put a tall arbor there. I've planted the corners with four Mme Alfred Carriere which I hope will grow vigorously and evenly into something well suited to growing on an arbor. There's another spot where a small path breaks from the main one which I have framed with two Blush Noisette roses. There are multiple copies of Don Juan in the garden simply because I like the idea of a fragrant red climbing rose. In a spot at the back of a deep bed by a fence I recently planted three Graham Thomas, my first execution of David Austin's idea of planting his roses in threes. Twelve feet away is Le Reve which I have seen growing to 35 ft at Roseraie de l'Hay. I thought GT needed some mass to stay in scale.
There's a spot in the garden where I have planted cerastium tomentosum, a silvery groundcover that grows wonderfully in our dry climate, making tiny white flowers in the summer. One Lili Marlene has been growing among these plants and just yesterday I added another. There's a spot at the other end of the garden where six Europeana grow among artemesia. This combination is more successful because the Europeana makes dark purple foliage that works well with the silver foliage of the artemesia. A triad of Claire Austin is in the same area.
I purchased five Day Breaker with the idea that I'd plant them in a certain bed. But by the time they arrived, I decided to use the bed in a different way, so now they are scattered in twos and threes about the garden. I increased my count of Rainbow Sorbet and Coral Crown to three this year. And I planted Double Delight in a triad. I only planted two Barbara Streisand because I wanted Paradise to complete the triad.
I find striking a balance between making a scenic garden that would make sense to, say, a landscape architect, and collecting good roses in their many varying styles and colors is not trivially easy. But when things work it can be quite rewarding.
