Keeping Singapore open creates time to reinforce the ground campaign as well as the fleet. Britain could draw on British, Indian, and possibly American formations, and the later scale of William Slim's Fourteenth Army shows how many resources could eventually be deployed in the region. That later strength was unavailable in early 1942, and some of Britain's best hot-weather formations had already been redirected to North Africa. The fleet would need to buy time for positions, training, and supply before those reinforcements could matter.
Notable Point · 53:55-55:55
A surviving Singapore buys time to rebuild the ground defence
An open base can receive British, Indian, and perhaps American troops, but reinforcement still depends on training, supply, and defensible positions.