Watching some pacific theatre right now. The amphibious beach assaults of Guadalcanal and Tarawa were indeed before Normandy. The Tarawa landing was a disaster because they made a huge mistake arriving at low tide forcing the Marines to get out of their landing crafts early. Wading thru the water with sharp corals all around, the awaiting and dug in japs mowed several hundred marines down before they ever got to the beach.

The saipan landing went much better which I think was just a few days after Normandy.

After that there was a disagreement between McArthur and king as to what to do next. King wanted to go take Formosa (Taiwan). It would have provided a base where bombers could reach Japan. But McArthur wanted to do more island hopping including the Philippines.

I think king's plan could have worked because even though the islandstill would have remained undefeated, kings plan would had them isolated. If king's plan had been implemented and had been successful, over 200K lives would have been saved. Maybe McArthurs promise to the Philippines should have been delayed?