ORIGINAL: Cuttlefish
I was taking another look at the AE screenshots and noticed to my delight that my home town is now on the map! I was puzzled by that for just a second but then I remembered nearby Adair Village, which in World War II was Camp Adair. During the war it was an infantry training center and POW camp and was also the second largest population center in Oregon (behind Portland). The current population is under 1000.
You are exactly correct about why we added Corvallis. There are "Camp" units -- fixed base forces -- at Corvallis, OR, Ft. Lewis (Tacoma), WA and San Luis Obispo and Ft. Ord CA. These were the main training centers on the West Coast.
During the course of the game four different US Divisions will appear in Corvallis. These are the four infantry divisions that formed and trained in Camp Adair and nearby Camp White before deploying overseas. Since three of them went to Europe you'll only get to use one of them unless the Japanese are foolish enough to invade the West Coast.