The build gives the fictional ship additional torpedoes because it is described as a torpedo ram. The tactical trap appears immediately: the torpedoes reach only about one and a half kilometres, while the six-inch and ten-inch guns can engage much farther away. Inside that short envelope a torpedo cruiser might dominate, but an opponent has every incentive to refuse the approach and keep firing. A close-range weapon can be devastating, but a ship built around it must solve the problem of reaching its target under fire.
Notable Point · 28:02-31:18
Torpedo rams and the engagement-range problem
Thunder Child's torpedo-rams are formidable only at very close range, where they must survive longer-ranged gunfire to strike.