The change here seems to be that holding Guam, Mindanao and a large part of the Dutch East Indies has enabled the U.S. to send adequate supplies and more troops to Luzon. It would be nice if you could supply some details on the logistics of this, and also on how convoys to the Philippines would be able to fend off Japanese air power on Luzon and the threat of still existing Japanese aircraft carriers.
Also, you say U.S. subs were delivering supplies to Bataan and then going hunting for Japanese ships. How are they able to deliver significant supplies while still having adequate torpedoes for their supplemental mission?
I have often wondered if subs could have been used effectively in a non stop shuttle of supplies to Bataan--how much could they have delivered by prioritizing the most important supplies (food, ammo, mortar shells). At the time of Pearl Harbor the U.S. had 73 subs in the Pacific, 38 elsewhere and 73 under construction. Say you had 50 subs doing nothing else during the siege....how much in the way of supplies could they have delivered? How much longer could the U.S. forces have held out? And as they held out, how many of the subs under construction or those from other theaters could have been brought into the shuttle service?
Also, could a system have been devised by some genius to pack the maximum number of supplies into a sub (including into the torpedo tubes)? Could the number of sailors have been cut back since the subs would not be on hunter-killer missions, so as to provide more space for supplies? Say Bataan holds out until early May and by this time the U.S. shuttle service includes 90 subs, each carrying one-third more supplies than the subs in OTL that visited Bataan?