I've recently become fascinated with warships, and I noted a very striking similarity between the Admiral Hipper-class heavy cruiser and the Bismarck-class battleship. Both have very similar superstructure configurations, two fore and two aft turrets, and a single smokestack.

For reference, here is a profile image of the Bismarck, and here is a profile image of the Admiral Hipper.

Both have tall superstructures, the same low bridge behind the B turret, a large, relatively flat area behind the smokestack, and even that giant walkway that Bismarck has just behind the bridge.

So, I guess my question is this: Who designed each of these ships? If they weren't designed by the same person, then why are they so similar?

Also, is there a better place to ask this question?