A three-knot superiority is presented as the margin needed to dictate an action, so a nominal 25-knot requirement becomes a 26-knot design target with allowance for shortfall. That margin lets the faster ship choose whether to close, disengage, or control the pace of battle. The machinery demand pushes far beyond ordinary battleship practice and anticipates the logic later associated with fast battleships. The Queen Elizabeth class is offered as an example of the risk created by only a marginal paper advantage.
Chapter · 15:48-20:27
Why the British battleship aims for 26 knots
The response needs roughly a three-knot margin over a 22-knot Dante Alighieri so it can control engagement range and battle pace.