Funnily enough they did try to do agile design with these warships. They started building the first one before they figured out the whole design, with the idea

Funnily enough they did try to do agile design with these warships. They started building the first one before they figured out the whole design, with the idea they could update as they went. It was an absolute disaster. They had to redo a bunch of work to fit in changes they didn't anticipate. Now all the early ships are unique, making maintenance worse. Turns out Agile depends on a low cost to refactor. It's easy to make a function body bigger. It's very painful to make an engine room bigger.