The Royal Navy's Type 45 Destroyer

(also known as the Daring class) is widely considered one of the world's premier air defense warships, if not, the best in the role. The ship excels at AAW (anti-aircraft and anti-missile warfare) owing largely to her high-mounted SAMPSON radar and S1850M radar, which offer outstanding detection capability.

Her primary weapons are her Aster missiles: Aster 30 for long-range area defense and Aster 15 for close-range self defense. These missiles have such a high Pk (probability of kill) that it's standard Royal Navy doctrine to fire a single missile per target (compared to USN doctrine to fire a minimum of 2 missiles per target to guarantee a kill).

But AAW aside... these ships are unable to fulfill any other role. The retirement of the Harpoon in 2018 leaves these ships without anti-ship capability. She relies on the embarked ASW helicopter (not included) for protection against submarines. Her radars can detect ballistic threats, but her Aster missiles cannot engage them. There was a proposal to add a Mk 41 VLS which would have allowed the ship to carry Tomahawk land attack missiles, but as we can see this hasn't happened.

Thus, in my opinion, the best composition of a destroyer fleet consists of a Type 45 destroyer for dedicated air defense and an AEGIS warship (Arleigh Burke) to fulfill other roles in addition to air defense.

Controls

Throttle: Move forward
Brake: Slow down/move backwards
Yaw: Steer
VTOL/Trim: Traverse/elevation of 4.5 inch gun
Landing Gear: Navigation lights;on by default when you spawn in
Action Group (AG) 1: VLS for Aster 15s and 30s
AG 2: Port side Phalanx CIWS; mouse as joystick to aim; has its
own camera view
AG 3: Starboard side Phalanx CIWS; mouse as joystick to aim; has
its own camera view
AG 4: Port side 30mm DS30M; mouse as joystick to aim
AG 5: Starboard side 30mm DS30M; mouse as joystick to aim
AG 6: Navigation radars;cannot be disabled once enabled
AG 7: SAMPSON and S1850M radars;cannot be disabled once enabled
AG 8: Increased maneuverability, use this in conjuction with flank
throttle (100%) for high-speed emergency defensive maneuvering;
also enables a gyro that allows you to turn at low speeds/idle;
on by default when you spawn in

Sorry if the controls are hard to understand, comment below if you have any questions and I'd be happy to help.