Since Western Europe was a crossroads of invasions and migrations for centuries, it's much harder to make distinctions among the various ethnicities and nationalities living in that area. The fact is, the French and Germans for instance have a largely similar genetic makeup, being a mixture of Celtic/Gallic (Celtic Gauls lived throughout what's now France, southern Germany/central Europe, and northern Italy), Germanic tribes (the Franks who gave France its name were a Germanic people who settled there and intermingled with the Romanized Gauls or "Gallo-Romans"), and to a lesser extent some admixture from Romans and other groups who traversed and conquered the region.

I tend to think that "Europe West" DNA is more of a signature of descent from the original Celtic/Gallic peoples of the region. There's also a lot of Scandinavian admixture in Europe West (Germanic tribes like Franks, Normans/Vikings, etc.), as well as Great Britain (geographical proximity), and Italy/Greece and Iberian (more so in southern France - ancient Iberian tribes and Greek/Roman colonists in places like Provence).

Europe West is really a crossroads of peoples and groups, hence the reality that anyone looking typically Swedish or typically Italian could easily pass as a Frenchman.