I’ve seen a lot of posts and articles about having a strong style. Finding your voice and sticking to it, creating consistent work, focusing on one medium. While I understand from a marketing point of view it makes it easier, as an audience will more readily recognize similar work as yours, doing just one thing still seems somewhat contradictory to me.
A number of very well-known artists, though best known for one medium or style of work, actually divided their time between two or three different things, or found their style developed and changed over time. Matisse painted, and sculpted, and he later did collage on paper. Emily Carr painted, but also made pottery, which was easier to sell than large canvasses. Picasso went through distinct and different phases in his work.
When you're applying to shows, or deciding what to show with what, selecting works that relate to one another certainly makes sense, and ideally demonstrates a progression throughout the work, or captures a specific period in your development as an artist. This shouldn’t mean, however, that older or less popular work is irrelevant and should be kept in storage, painted over or thrown out – everything you’ve made informs the next things you try, helping you find new directions, or letting you figure out what works best.