As far as I can discover the first 40mm Bofors USN Mount was not installed until June 1942 on board USS Wyoming, at least two weeks after Midway.The "normally meticulous" Gingrich and Fortschen had the USS Enterprise armed with 40mm and 20mm guns in Dec 41. And in another series completely missed that one regiment and half of another in Custer's brigade were armed with Spencer rifles.
However, their a hell of a lot better than some other AH writers, Tsouras, Conroy, or Harrison.
(And some posters here)
And didn't go completely "American Exceptionalist".