Once the bombers arrived, Force Z could not produce enough fire to break their formations before the attack runs. A Dido-class anti-aircraft cruiser might have helped, but a single ship probably would not supply the necessary volume. Only the weapons on the engaged side of each ship could bear, while dozens of aircraft approached from chosen directions. Several AA cruisers might begin to substitute for the missing outer defensive layer, but one extra gun platform would not solve the absence of fighters.
Notable Point · 37:50-38:48
Why AA cruisers could not replace the fighter layer
One Dido-class anti-aircraft cruiser might add fire, but dozens of attackers and limited firing arcs still demanded fighters or several heavy-AA ships.