Why better anti-aircraft weapons could not save scattered ships

Why did British ships seem so weak in anti-aircraft weapons and control during the Indian Ocean raid?

Exposed, penny-packet formations created the main danger. Staying beyond aircraft range was safer than relying on the ships' anti-aircraft fits.

The ships' anti-aircraft outfits were not exceptionally weak for the period. Their deeper problem was operating in small, exposed groups against the concentrated strength of Japanese carrier aviation. Dorsetshire and Cornwall could have taken a longer route toward Somerville that added hours to the rendezvous but carried them beyond practical strike range. For isolated ships, distance reduced both the chance of detection and the enemy's ability to mount an attack, making route choice a stronger defense than another increment of anti-aircraft weaponry.