The AI flies a different engine model, this had been announced ages ago during the development of the sim.
This is done for performance reasons: enabling CEM costs as much as 10 FPS on some PCs and that's just the player's aircraft. Imagine what would happen if every AI aircraft had full CEM and on top of that, needed an AI smart enough to use it. We'd be limited to 4vs4 dogfights or less
The way it works is that instead of having the AI conform to all the limitations of CEM (and having to use up even more processing power to have an AI that can work with these), they just give them a set of artificially imposed limits so that they simply don't "cheat".
In other words, the AI only knows what is a reasonable speed to fly and flies that speed. It won't operate cowl flaps and manage temperatures and operating limits in the same way a real/human pilot will, because it would bring any PC to its knees.