A huge number of those companies will be dormant, wholly owned subsidiaries, or one-man-band operations (e.g. contractors with limited companies)

Of course it's a moot point because companies don't have citizens' best interests in mind. They want cheap labor, big markets, lobbying power, and regulations that raise barriers to entry for their industries.

On all of those counts, the EU is fantastic for big business, but not necessarily for ordinary citizens.