Could the United States have both sixteen-inch Lexington battlecruisers and twelve-inch Alaska-class large cruisers?
Short answerYes; the Alaskas could reinforce surviving Lexingtons in fast carrier groups rather than duplicate them.
NotesThe proposed American force retains sixteen-inch Lexington battlecruisers while adding twelve-inch Alaska-class large cruisers. A modernised Lexington and an Alaska could support each other in a fast group. Pairing them with a Yorktown and Wasp, then adding destroyers, produces the suggested four-ship core. The expectation is that this force could defeat most opponents encountered in the Pacific and fight off others.