Could Courageous-class hulls have carried 9.2-inch guns?

Could Courageous-class ships have been redesigned with four twin 9.2-inch turrets and heavier protection?

Yes; it would be a relatively modest redesign of the large light-cruiser hull concept.

Fitting four twin 9.2-inch turrets and greater protection would not require a radical departure from the basic Courageous-class hull. Later Neptune-class thinking indicates that the large light-cruiser concept could support further development. The proposed changes would turn speed and hull volume toward a more conventional cruiser armament and protection balance. This design lineage shows that an unusual original requirement did not make the hull incapable of a different role.