As a teacher, I can say that games are a great way to get kids interested in the stuff they're about. The difficulty of teaching certain curriculum can drop silly dramatically if a game or television series about that subject gets popular. For example, it is definitely easier teaching feudalism in middle school now that everyone and his mom loves Game of Thrones. Back when Sailor Moon was popular, elementary school students knew their planets before first grade.
But especially a paradox game would make a terrible education tool. It's the kind of game that pretty much requires you to be invested in it already before you play. They have steep learning curves, uninviting UI (compared to mainstream games), and take a lot of time to play. I'm pretty sure their target audience is like 25-50, too. Sure, the nerds that play them probably get motivated to learn more about history, but that's a tiny percentage of your audience in education.
CIV 5 is a way better education tool. It's on console with an easily interface to navigate, simple enough a 10 year old could have fun playing it, and I think it even has a glossary of history that they can read by pausing the game.