A focused range needs contrast, not just more products
When every listing is presented as the main attraction, the assortment stops communicating a point of view. Give each product a role: a feature that leads the section, an established reference, a companion product or a measured test.
The roles do not predict sales. They help the store decide how much presentation effort a release deserves and whether two products are doing the same job. If they are, one may be enough for the current edit.