Could Britain build and commission a class derived from HMS Unicorn in time to help?
Short answerProbably yes, because Unicorn was already under construction and later British light fleet carriers showed how quickly several hulls could be produced.
NotesHMS Unicorn was already under construction, giving Britain a design and active programme from which related carriers might follow. Several could probably be completed in time to affect the war. British light fleet carriers were historically built quickly. Existing design work and active construction could therefore shorten wartime mobilisation and expand carrier numbers sooner.