Why a Flower-class book began with Sackville

Why did the Flower class become the first book subject rather than the Black Swans?

Visiting HMCS Sackville convinced him to begin with the Flower-class corvettes and leave the Black Swans for later.

Walking aboard the preserved HMCS Sackville changed the order of the planned book projects. The Flower-class corvettes would come first, with the Black Swans following later. The choice arose from a direct encounter with the preserved ship rather than an abstract comparison of possible subjects. A museum visit can turn a broad research interest into a concrete writing project.