Why Tribal-class destroyers carry their aft guns so far back

Why are the Tribal class's rear guns mounted so far aft?

The guns must fit around machinery and structural supports below deck; their position also contributes to a cruiser-like silhouette.

The Tribal class's aft guns had to fit around boilers, torpedo tubes, and the ship's internal layout. Each mounting needed supporting space below, while the rudder flats and propeller supports also occupied the stern. Those competing demands limited the available positions. The resulting outline also resembled a cruiser at a distance, especially with the central portholes shut; the improved Leanders provide a comparison with two funnels.