In all the CM games you play hypothetical scenarios. The terrain is not exactly the same, the troops are not the same, nothing in the same as it happened. It might be similiar. And also what the troops do are not what they did in real life. You still playing hypothetical because how you direct the troops is not what happened. If you imagine you are playing a real battle that happened is like believing in Santa Claus.
The only place where you play real scenarios are when you watch a documentary where everything is how it was.