I can see Joan of Arc as a Great Leader for the French civ, but I never bought her as ruler. Joan of Arc was a military leader. She may have had some influence over the Dauphin, but she could hardly be said to have ruled France.
I voted for Louis XIV in the poll. He strengthened the government of France and turned it into a unified state, and also consolidated the colonial territories, making France a world power.
A strong case could also be made for Napoleon, however. Though it's true that far too much of his focus was on his doomed wars of conquest, and, like Alexander, the massive empire his armies built fell apart once his reign ended, I would also have to say that it would be disingenuous to say that he was 'just' a warlord. Though he did crown himself Emperor, he still believed in freedom for the people, and he did a lot of good for the common folk of France. The French legal system is still based on the Code Napoléon even today.
So a case could be made for either Louis XIV or Napoleon, in my opinion. As I say, I lean toward the Sun King, but if they did change it to Napoleon, I wouldn't complain. I do complain about Joan of Arc, though. Ruler of the French civ is a title she has no rights to. She should be one of the Great Leaders that can appear after a military victory, and I would strongly support her in that role. But ruler of France itself she was not, and should not be.