The Starters that I think are likely with some fair reasoning

Grass
Serperior - Rose of Versailles. Very obvious

Meganium - Grass cultivation started in France or something

Water
Empoleon - Napoleon. Very obvious

Inteleon - This one is admittedly a guess but I could actually see it getting a regional based off Arsene Lupin (The French Phantom Thief/Detective)

Primarina - Another guess but I could see it getting a regional based off Phantom of the Oprah

Fire
Incineroar - The French love Wrestling

Cinderace - The French love Soccer

Blaziken - Rooster is the National French Bird


Does anyone have any other suggestions?