by T. A. Gardner » 17 Oct 2019 20:51
I'd say the Japanese still sink force Z starting with the Illustrious. The IJN bomber pilots would have zeroed in on the carrier first and either crippled or sunk it before going after the battleships. The few planes on CAP, as was British practice, wouldn't be enough to stop them. The Destroyer escort is worthless in contributing to the AA defense, and the whole formation would have maneuvered independently to evade attack, just as they did historically.
Once Illustrious can't launch planes, the Japanese either come back with fresh waves of planes, or the ones still with bombs and torpedoes go after the battleships. They sink those just like they did historically.
The RN needs more than a carrier with a relative handful of fighter planes aboard to fix their problems with Force Z. The formation needed to be steaming in one that would maximize air defense, and that is the circular one the USN was using.
Next, Force Z needed destroyers that could put up an effective AA defense, and that wasn't happening. A few obsolete 3" guns manually aimed, a few pompoms and 20mm aren't going to contribute much, if anything, to the formation's defense against air attack.
Repulse also has a badly deficient AA battery at the time.
Had Zero's been sent to escort the bombers, that would just add insult to injury. They would have dominated the small British CAP, particularly the rather unwieldy Fulmars. Then the bombers sink or cripple the carrier and it's fins for Force Z.