As noted above, they are the "same" ship in much the way that a B-17D is the same plane as a B-17G.
Or in the same way an M-3 Grant tank is the same as an M-3 Lee.
Truly, the differences are far larger, really--like FW-190A to FW-190D; an M-3 light tank to an M-5.
The length of time it took to build each of the Iowas meant there were changes between each one 9the way the bridges were enclosed or open being just one). And all that before taking the service life into account., which encompasses more changes.
New Jersey was activated four times, and has changes which reflect that fact. Enough to spot the differences in WWII; Korea; VN; and 80s-90s an interesting model collection even at 1/700.
Now, scrunch down to, oh, 1/1200 scale, and you could wing it and have any iowa represent the other (those 24" WWII numerals only being 0.02" tall more an act of faith; the 72" shaded numbers at 0.06" tall scarcely better).
That's my 2¢ at least--you'll still need another three for a beverage at Starbux . . .