Definitely! That's perfectly fine, I was asking mainly in the vein of seeing what is and isn't possible - as before, CO2 is more a battle simulator than a campaign simulator. That being said, it looks to be excellent for simulating multi-day engagements if not actual campaigns. That opens up a lot of possibility from the easiest, WW2 and 20th century conflicts, to mod to pre-modern era battles (thinking Civil War general type battles, Napoleonic, etc.)
In any case, a Philippine campaign would really be best split into an Initial Landings scenario comprising the entirety of Luzon and allowing the USAFFE player to take MacArthur's role - try to stop the Japanese on the beaches, failing that then retreating with his force intact to Bataan (the Calumpit bridgehead being key to the situation) while the Japanese with stronger and better forces is forced to decide whether to 1) capture the strategic objective of Manila, 2) destroy MacArthur's forces so they no longer pose a threat, 3) accomplish this before the scenario ends (around the time that the 48th Division was withdrawn for the Java campaign) - which, again, were the problems that General Masaharu Homma faced in 1941.
Scenario variations would include making the "Pensacola Convoy" forces available to MacArthur, making MacArthur adhere more to War Plan Orange 3 by pulling his forces south of the Bagbag River/Calumpit Bridge and creating a defensive line there that the Japanese must then flank or crack (though this might mean... amphibious landings or a workaround thereof) and a Fortress Manila option which sees MacArthur not declaring Manila an Open City but fortifying and defending the old city.
Definitely worth exploring!
Again, many thanks guys!