Hmm, that map sort of reminds me of Empire Earth. In one of the expansion pack mission, I was to stop enemy transport ships landing on my little island, and believe me, those boats held more than two unites.
Anyway, the only difference, was 1) there were Air Craft Carriers, 2) I had Anti Air Guns/Tanks (they are useful, unlike AW), and 3) I had an air port (with no air units).
This mission was based on the protection of Midway Island during WW2.