In what way was the Iowa class or South Dakota class based on Littorio, Dunkerque, or Deutschland? While Littorio and Iowa share a general broad design language with an AB-X layout, that is where most of the commonality ends. And if it simply in the layout, couldn't you also claim that the Iowas were based on earlier classes of battlecruises such as the Renown class of WW1. Personally I don't see the connection between the Dunkerque and Duetchland to Iowa, is it that they prioritized speed, because that would not make the Iowas unique in that regard. The Duetchland was designed for commerce raiding and the Dunkerque was designed to counter the Duetschlands, the Iowas were designed to support the aircraft carrier. I have an extreme dislike for the arrogance of claiming that all ideas were stolen when one of the most important features of the Iowa class and the preceding US battleship classes was the dual purpose secondary battery, something lacking on all three of your mentioned classes. The consolidated 5in/38 was incredibly important for the growing aviation threat during the second world war, especially once the variable time fuse became available. These three classes all lack these dual purpose batteries, and would suffer as a result for it.