I think it’s too early to say whether the Iowas will really need the nuke shells.
Neither the Iowa, nor any of its contemporaries, are in-game yet, we don’t know how they would really perform compared to one another.
Iowa’s characteristics would make it pretty similar to Scharnhorst-- extremely fast and very durable. It may not need those shells to be dominant in the future Naval meta. But we won’t know for sure until we’re there.
The thermal and night vision resolutions we have ingame are way higher than what they should be and the pods that would be available to the planes we currently have (assuming we stay period correct) would be extremely limited in their performance
It would fair equally to everyone else against the Yamato. I don’t know exact 1v1 performance Vs Yamato for everyone but why the US only should get a very powerful shell would be unfair. In otherwords. What can Britain, Soviets, Italy and France get to counter Iowa with a nuke shell? Harpoon/EXOCETs?