Selecting the French nation may result in bonuses related to Training and Friendship. Since the French nation reduces the time it takes to train an Army by 20%--and that is highly important when you are in a battle spree. Aside from the reduced training time, selecting the French nation also increases the maximum amount of allied troops by 3.
The unique unit the French nation possesses is the Chevalier which has an extremely high amount of hitpoints. This unit will evolve into the Heavy Chevalier, Elite Chevalier, Guard Chevalier, Hussar, and St. Chamond.