Yes, DA. I certainly do share your view about looking at the trees and the forest. That's why (again I say this) I pointed out that the only way that I could see was to play fast and loose with historical facts.
Sticking closer to historical facts, the days of Mac's forces in the PI were certainly numbered. Mac underestimated the capabilities of the Japanese and his Filipino and American troops paid the price.
At what point then in the campaign could an offensive by the US garrison do the most good?
Logically, it would have been at the time when the Japanese were still landing and not established a firm beach head. However, the reality was that the beach defenses collapsed utterly. Only when the Japanese were breaking through and racing down Luzon did Mac finally order his forces (the North and South Luzon Forces) to fall back into Bataan.
The next best time to go on the offensive against the Japanese is when the Japanese units were strung out during the race.
The US garrison would've been consolidated by this time at their first defense line in Bataan. And that would've been in Layac Junction.
The main thing to note, however, is that whatever gains this hypothetical offensive might have had would have been fleeting, if not temporary.
Mac's forces were surrounded. They couldn't get out. No friendly units can come in.
That's why I propose that it would've been better for the US garrison to hold first and hope to last until the start of the rainy season (around June). By this time, the US and its allies historically had more options than they did in the beginning.
And if the forces in the PI were still in good shape after the Japanese debacle in Midway, it's entirely possible some things could have developed. The key to the Bataan garrison's survival wasn't an offensive but to still be in fighting form once the US Navy defeats the IJN.
Personally, I don't have any other ideas left for this what if. I've said what I know. I certainly learned a few new things and been forced to look at old facts and data under a different light thanks to John and DA.
The survival of the Bataan garrison and the launching of a hypothetical offensive depended on two main factors: having an intact air force and a secure route for the US Navy to bring a relief convoy through with minimal loses. However, the Japanese removed these factors from the US with the successful Japanese attacks on Clark and Pearl Harbor.
PS Took me a while to post. Have not been able to post as often as I had before. Been busy lately with taking care of my dad who's in hospital.