Kido Butai waits for the US relief force

How would Japan use Kido Butai if it attacked the Philippines without attacking Pearl Harbor?

Kido Butai could dominate the South China Sea or ambush the US fleet as it crosses the Pacific to relieve the Philippines.

Leaving out the Pearl Harbor operation gives Kido Butai other possible roles in the opening campaign. One proposal is to dominate the South China Sea. Another is to wait in the Pacific for the American response force and begin wearing it down as it approaches. This is linked to the Japanese attrition doctrine followed until roughly 1940.