The attack on Port Moresby which I used as an example was a part of the initial Jap offensive, when they still had superiority in almost every aspect. The place had lots of open space that would have made for excellent LZ, and was easily within reach of both Buna and Milne Bay, had the Nip ever captured it.

Doesn´t sound to me like the kind of brew that would deter the Japanese, taking into consideration his predilection for maneuver warfare, specially of the outflanking kind.