These battlecruisers are being used as new heavy cruisers because no satisfactory heavy-cruiser hull was available. The substitution produces a sharp surface-action mismatch: range, broadside weight, and secondary guns let the larger ships dominate smaller heavy cruisers while still respecting torpedo danger. The French ships cannot reply until they close, while the British design is already using its main and secondary batteries. Filling one role with a much larger ship solves the design problem at the cost of a very different force package.
Notable Point · 47:03-49:13
Battlecruisers as heavy-cruiser substitutes
The stream uses oversized battlecruisers to show what happens when a navy cannot get the heavy-cruiser design it wants.