Manual work in British and American heavy-gun loading

Was the American 16-inch loading system more manual than the British 15-inch system?

Not substantially. Both were similarly semi-automated, with manual work occurring at different points in each system.

The American 16-inch system was not markedly more manual than the British 15-inch system. Both were forms of semi-automation. Film can make their labour requirements look different because each navy placed people at different stages of the loading cycle. Combining the strongest features of both arrangements could reduce crew further, making workflow more important than a simple manual-versus-automatic label.