The Fleet Air Arm had begun ordering newer aircraft after regaining control of procurement in the late 1930s, but war forced manufacturers to mass-produce what was ready. Britain had to supply forces that were already using and losing equipment while its factories were exposed to attack. It could not simply halt an established line, retool at leisure, and wait for a technically superior replacement. Production of the older type had to continue until the successor could take over, whereas the United States gained additional peacetime development time before entering the war.
Chapter · 6:01-7:28
How wartime demand freezes available designs into production
Britain had to keep current equipment flowing while introducing replacements under bombardment and combat losses.