I want to thank beelee for taking the time to make the "no defense unit " an option in WAW v3 variant. Sorry that it's taken me a while to try it out.
Now that I have, I have to say that it made a huge difference in how the AI purchased units and therefore it improved the gameplay.
Before, with the defense unit available as a purchase, the AI mostly bought the defense unit and a few infantry and some artillery and armor.
With the "no defense" option, on the first round alone, the AI purchased infantry, artillery, armored car, armor, paratroopers, a carrier, sea transport, dive fighters, a bomber and a few big bombers.
This, of course, makes the game much more enjoyable.
The AI still has a few issues complying with the rules of the game but all-and-all it's a big improvement.
Thanks again for your time and effort.