Why underpowered 1920s carrier aircraft could need twin engines

Why would an Eagle-style Admiral-class carrier conversion encourage twin-engine aircraft when 1920s piston engines were underpowered?

Limited power per engine is part of the reason to use two: the combination could carry a torpedo farther and improve the crew's chance of returning after an engine failure.

Underpowered 1920s engines could make a twin-engine aircraft attractive when one engine could not carry a torpedo over the required distance. Two engines offered different combinations of power, range, and efficiency. They also gave a crew a chance of returning after one engine stopped. The comparison with later twin-engine naval strike aircraft concerns that extra survivability, without claiming that the arrangement would always produce greater speed.