A stronger ABDACOM complicates MacArthur's command

Would a Force Z-centered ABDACOM sideline Douglas MacArthur?

It would create serious difficulties for MacArthur because a four-star British admiral would already command the coalition forces fighting there.

Coalition command remains a problem even with a stronger fleet. Phillips would already be a four-star British admiral leading forces in combat. His rank and operational position would make ABDA Command more British in character. That established authority would make Douglas MacArthur's later bid for theatre command harder to secure.