Reading O-class speed and displacement claims sceptically

Is it reasonable to doubt the projected 35-knot performance of the O-class battlecruiser?

Yes; both displacement and speed should be treated as optimistic design claims rather than proven performance.

The published O-class figures invite the same caution as optimistic claims for Bismarck's displacement. Projected displacement and speed describe an aspiration, not tested performance. A completed ship would more likely be an incremental battlecruiser development of the Bismarck design. The advertised 35 knots should therefore be treated as a design goal rather than a demonstrated result.