Could the King George V class have used a different turret layout?

Would making C turret a twin have been better than reducing B turret to two guns on the King George V class?

No; he prefers three triple 15-inch turrets, ideally using an upgraded weapon that could also modernize the Royal Navy's existing 15-inch capital ships.

Simply moving the reduced twin mounting aft would not solve the design problem. The preferred alternative is three triple 15-inch turrets using a modernized weapon that could also support the Queen Elizabeth class, Revenge class, Renown, Repulse, and Hood. Common ammunition and support infrastructure can matter as much as the nominal gun arrangement.