I want to try tasting them side by side. A pecan is a type of hickory, and there are 5 or so other types of edible hickory nut, too. We also have another type of walnut called a butternut, or white walnut, too. You can buy juglans nigra nuts, but I dont think you can buy any of those other species.
I think juglans regia is what you have in France, but there are probably many different varieties since they have been cultivated for many years in many different countries for nuts and wood.
Juglans nigra is grown in France as a street tree and for timber, so you might be able to find some nuts yourself with a tool like iNaturalist.