The whole way France is handled in EU4 is pretty bad. Historically, while France was regarded as a/the superpower from the 11th to the 17th century, it was also a very divided country, plagued by internal conflict, cultural, social and religious unrest.
In the game, this is replaced by a few vassals, an culture group that means Britons and Francomtois are considered french even in 1444, and OP religious decisions that makes the whole reformation a non-event. Ideally, France should have something like Ming's three factions.
Mind you, this is not nearly as bad as Austria being a world power in 1444. But still. I wish France had more fluff.