If Force Z had survived: carrier support and Singapore's guns

What might have changed if Prince of Wales and Repulse had survived Malaya?

They could have strengthened the eastern force, changed its command, prompted greater air support, and potentially added heavy guns to Singapore's defense.

Had Prince of Wales and Repulse reached the Indian Ocean, Admiral Phillips would probably have remained the senior commander instead of Somerville. Their survival after a heavy air attack would also have strengthened the case for assigning carrier support and a dedicated carrier commander. A damaged ship might have remained at Singapore rather than withdrawing immediately. Its 15-inch high-explosive ammunition could then have added powerful landward artillery to the defense. Every part of this outcome remains counterfactual.