One proposed explanation for the Dominion choice is that the commerce-protection requirement narrowed the procurement decision before alternatives received equal consideration. Indefatigable fitted the established category of a cruiser carrying battleship guns for trade protection. Lion could do the same job and fight enemy battlecruisers, but its wider capability lay outside that narrower description. The Dominion ships were ordered in August 1909, and Lion was laid down that November, indicating how far the newer design had already progressed. Australia and New Zealand were not laid down until the following June. Their subsequent good careers do not remove the question of why the less capable design was chosen.
Notable Point · 20:27-28:18
How a commerce-protection label narrowed the ship choice
A commerce-protection requirement may have steered planners toward Indefatigable even though Lion could perform that mission and fight peer battlecruisers.