Mrchntmarine
the most historically correct WWII era ship kits?
If you mean like the way you can pick and choose between Spitfire or PzKfz IV kits, there isn't one. Zero. None.
Ships are just too unique, even when built "to class"--those classes can be as few as two, but are typically under 25, and even at the same yard the one or two years spent on the first will change the next.
This wil scan harsh; that's not entirely my intent. The better way to frame the qustion is, "I want to build [ship], what are my best options?"
Let's pick one. IJN Yamato.
From memory (which may be fickle and faulty) she's available in--injection moulded plastic:
1/800
1/720
1/700 (I think three kits)
1/600 (maybe)
1/500 (nitto, maybe)
1/350 (either 3 or 4 kits, Tamiya has an old version and a new version)
1/200 (3 different kits, IIRC, one very old)
Pretty much there's AM for the 1/700 and 1/350 and 1/200 kits, if kit specific. And, it makes a big difference if you want the 1941 appearance or the 1943, or the 1945. Aftermarket for Yamato can set you back far in excess of the kit price, too.
Tamiya's 1/350 DD-445 Fletcher is pretty good right out of the box, for 1943. For 1945, less so. Tumpy's DD-537 The Sullivans is ok, there are some wobbly details as the kit cannot quite decide if it's 1943 fit or 1945 fit (and the color callouts are largely Impressionist). The England kit is actually much better, if an entirey diffferent ship, and type, and class.
Until fairly recently, if you wanted CL-52 USS Juneau (which made the Sullivan brothers famous) your only choice was 1/700, or very spendy resin. The various CL(AA) sister ships would require differing levels of surgery.