Herr Doctor said:snip
and we do not want the things go crazy and unhistorical (and unrealistic too) to please someone’s odd tastes…
But you don't quite get that that by definition all game outcomes are going to be ahistorical as long as you allow a "B" choice in events, as long as the AI can declare war on any nation that it did not historically declare war upon, or be a member of an alliance it was not historically a part of.
If you are seeking even a quasi-historic outcome in the 17th-19th centuries by starting in the early 15th, you are wasting time and effort, and actually taking a great deal of enjoyment out of the game by limiting a players impact upon the environment.
Nothing kills the joy of playing the game then getting the impression that no matter how hard you try you can't change anything in a real way. And by sledg-hammering deterministic paths, or overly deterministic ones into the game you have done just that.
The GC, is by definition the game type that the players that wish to see the most amount of historic variation are going to play. If people play it and are honestly expecting to have history play out as they have learned it they have made a serious mistake. History is a dynamic and living thing, it breaths, it moves, it evolves and changes. Because history is the story of people, and people live, breath, evolve and change.
The best and truly only way that you can guarantee that a player is going to see the Napoleonic wars in any game is to write a Napoleonic scenario and let them start at the appropriate year. Same goes for the 30 years war or any other epochal event. The conditions for those events to transpire are NOT fixed outcomes if you start in 1419! Does the 30 years war make much sense if you have a protestant Bavaria and Austria (which I have seen in a game or six)?
The most unrealistic thing is to expect to achieve a quasi-historic outcome in 1800 from a starting point in 1419.