But the base value is 16+5. That alone is already 21%. 17.4% is not enough to overcome that. No where near enough. Also, Fort Level is irrelevant, it's 1500. Maybe fort level 3 at most. Also, so is Cathedral, again it's 1500, and Cathedral is a solid 100 years away? It's still pretty far from possible, even if theoretically they get every single bonus. I don't think it's even possible still.
(Not to mention the permanent -25% they are gonna have from religious fanatics for the rest of the game XD)
The game decided that France will be Protestant in that game. Paradox has spoketh.