the idea is not to defend every landarea, only the vital ones (italy, germany), then have meches + tanks + planes in range so that you can counterattack anything else.
it is not trivial for US to land in north italy if you defend it with 3-5 units, and are able to counterattack with 15-20 german planes + 20+ german landunits.
german mechs in w germany are able to counterattack most terretories in europe, if the german planes try to stay in range, then it is difficult to land.
the only two terrs that are not “covered” by this strat is norway and s italy. in s italy you need how much you need anyways, and for norway, if your fleet is alive, you can have 5-8 inf in finland, keep your planes within range and then be able to attack with about 25-30 units (depending on how many planes you have).
It is expensive to defend against an enemy that can land everywhere, so rather, counterattack than defend, if you are able to kill one load of americans, then the transports need 3 turns before they are back and able to threathen again.
