Yeah, the AI does... strange things. But that's not only the WWII planes. I practised dogfighting in the Mirage against an AI MiG-21 and it also does stuff that I cannot do when flying that plane.
The AI's flight model is a lot simpler than what you have, especially concerning stall and spin characteristics, and then they do not overheat their engines, they won't ever flameout (except when running out of fuel), and they can exceed the G limits for sensors (such as radar) and weapons.