If every Royal Navy aircraft became a Fairey Gannet in 1939

What if every Royal Navy aircraft became a Fairey Gannet in June 1939, with the necessary support systems?

Upgrade the carriers' arresting gear and obtain dedicated fighters, then use the Gannets' radar and strike capability to inflict much heavier damage on U-boats and surface forces.

Replacing every naval aircraft with a Fairey Gannet would give the Royal Navy a few hundred advanced strike and reconnaissance aircraft, along with radar and the supporting equipment specified in the question. Existing carriers would need upgraded arresting gear. Fulmars or another dedicated fighter would still be necessary, because fitting gun pods would not make the Gannet airframe suitable for fighter combat. Its engine could instead support the development of a separate fighter airframe. Radar-equipped searches would make German U-boats much easier to find, and HMS Courageous might consequently survive September 1939. Germany's invasion of Norway would probably fail under this greater air threat. At Taranto, Gannets could retain the slow approach while carrying more torpedoes or heavier bombs.