Surviving Force Z makes an Allied carrier counterstroke credible

How badly would the opposing navies be affected if Force Z survived and Allied carriers formed around it?

Japan would face a credible combined force in which the capital ships and three Allied carriers protected one another and could coordinate night and dawn attacks.

Surviving capital ships would give the United States a stronger reason to send Saratoga to ABDA, while the carrier would provide air cover for Force Z. Adding Illustrious and Indomitable creates a balanced three-carrier force with different operating strengths. Under James Somerville, the British carriers could mount a night strike. Saratoga could follow at dawn, presenting Japan with a much more dangerous operational problem.