Large autonomous combatants cannot be surged like torpedo boats

Could Britain develop autonomous systems in peacetime and then scale them rapidly when a larger fleet is needed?

Not at the size and complexity proposed: the missile, radar, and command ships still need warship-grade yards, systems, and long production lead times.

Large missile and radar ships cannot be expanded quickly once war begins. Torpedo boats and small commercial craft can scale rapidly, but military hulls with advanced sensors, launchers, communications, and survivability still depend on specialized yards and supply chains. Missile barges can augment the fleet, yet the command ship must remain capable enough to resemble the intended Type 83. Advance development is not a substitute for sustained production capacity.