Note that ships in the same class are rarely actually identical. There was also quite a bit of time since they were both built, and the later vessel no doubt incorporated changes / improvements on the design.
And then you get into the really fun stuff, where what's on the plans, and what actually got built are usually at least a little different... and maybe the as-built documentation was not finished correctly either.
They also sag. A half of a ship isn't as rigid as an entire ship. It changes shape in all sorts of unpredictable ways. There is lots of lifting and pulling before the two hulls line up well enough to start welding them together.
The overall structure should be basically the same though and any changes should be documented on a government contract like this so future maintenance and upgrades can be planned and built by any contractors.
And then you get into the really fun stuff, where what's on the plans, and what actually got built are usually at least a little different... and maybe the as-built documentation was not finished correctly either.