There was a WWI arena in Air Warrior. It was always almost empty. I didn't like WWI. The problem is that you have no forward-up view. To get a taste for what it's like, map your forward-up view keys (or hat or whatever you use) to straight down (so you are looking at your cockpit floor -- i.e., no view). Then go try some stallfights, where your most-used view is forward-up. That's what it's like.