What would Britain convert into aircraft carriers if Courageous, Glorious, and Furious had not been built?
Short answerIt would probably convert Admiral- or G3-class hulls, choosing whichever ships were farthest along.
NotesThe historical large light cruisers gave Britain hulls that could become Courageous, Glorious, and Furious as carriers. Removing those ships does not remove the need for carrier conversions. The Admirals or G3s could supply the replacement hulls, depending on which projects had progressed farthest when the decision was made. Early carrier growth often gained aviation capacity by sacrificing another capital-ship program.