Sisters does not necessarily mean identical – in fact many cruiser and up sisters differ to some degree, even as built.
Derfflinger had one less 5.9" per side and did not have a tripod until after Jutland, and then only a light one with a small top. Her partially cased funnels were of different heights.
Lutzow never had a tripod and had a fully cased fore funnel of even height with the aft funnel.
Hindenberg had a much heavier, much more spread out tripod and much less prominent funnel caps on even height funnels and a larger fighting top.
Bridge details differed among all three as well.
Some sources list Hindenberg as a separate, stand-alone class because of her significant internal differences. In reality the three ships are a series of ongoing improvements.
How these pan out in 1/3000? Dunno…. too small for me. But the lack of tripod could account for Lutzow's flatness.