Help me survive on the Philippines and Bataan!

[Longasc]

Any strategy suggestions and, maybe easier for starters, core composition suggestions?

I started out buying some Marines without transports and also a 75mm Anti-Tank gun (that was really useful to stop those Jap tanks) and a M3 Stuart. But that left me without airforce and low on resources.

[Erik2]

Any strategy suggestions and, maybe easier for starters, core composition suggestions?

I started out buying some Marines without transports and also a 75mm Anti-Tank gun (that was really useful to stop those Jap tanks) and a M3 Stuart. But that left me without airforce and low on resources.

I think is better to buy the cheapest, regular infantry and maybe a 37mm AA unit (that can switch to AT). As you discovered, you need to hoard your resources to be able to repair.
The early US scenarios are defensive ones, pull back whenever the heavy Japanese artillery appears. Don't hold on to objectives beyond the objective settings.
Defend behind rivers and the big tactical difference from PzCorps: Learn have to take advantage of the flanking rules, (blue crosses is good, red crosses not). The AI is pretty good at handling flanking in its attacks, watch and learn.

[Myrddraal]

The early US scenarios are defensive ones, pull back whenever the heavy Japanese artillery appears. Don't hold on to objectives beyond the objective settings.

This is key. You are performing a defensive action. It's very easy to fall into the trap of trying to hold on to every hex, but sometimes you have to cede ground to give yourself the tactical advantage. Yes, retreating can be painful, but not as painful as the Japanese heavy artillery (which has a hard time keeping up through the difficult terrain).

flanking rules, (blue crosses is good, red crosses not)

Another good point. AT tanks support adjacent infantry. If you have a friendly unit outflanking your enemy, and that friendly unit is not adjacent to any other enemies, they provide outflanking support, which will increases your odds of successful attacks.

[adherbal]

You have to play these early scenario with retreat on your mind, not destroying enemy units. Also keep your units in a position so they can be extracted quickly. Once a significant amount of Japanese troops have move onto the river hexes you have to fall back. If you wait until they start to push some of your units back from the riverbanks it is too late.

Use tanks and other fast, healthy units to form a rearguard while the slow units retreat - ideally using the roads. Use the fact that leaving a river hex takes 1 full turn, which prevents the Japanese from chasing you effectively. Fall back to the next river and repeat the procedure.

These maps are covered with bunkers, so falling back will allow you to use these against the Japanese. Use these static defenses as cornerstones in your defense each time you fall back.

[Longasc]

I will try the 37mm next and play the scenario again.

The next step after not overspending on expensive units was acceptance. Acceptance that the Japanese will cross the rivers. That I cannot just keep them on the other side forever. And yes, their artillery is dangerous.
Also planning ahead for retreat helped a lot to keep units alive and minimize losses.

There are a lot of showstoppers for the Japanese (read: bunkers) and I didn't utilize them at all last time. Things got way better now, and now I will try it again with small AT guns.

Thanks for your advice!

[Longasc]

I'm back on Bataan, lost no single unit and units are in good shape. Feeling good.

Bataan seems to be even more serious business. I am reading up the historical data about the battle, seems this one will be bloody no matter how hard I try.

[Qwer28]

Use engineers for destroid bridges and use mines. And heavy infanty is better for defend then marines.