The U.K. needs the E.U. more the E.U. needs the UK.
Other way around. We are a huge customer. If they lose us behind a tariff wall of their own devising, then their manufacturers will crash and burn.
Markus Kerber of the German BDI has already acknowledged this, though perhaps not in such colorful language.
They have a trade deficit but there's not a huge difference between exports vs imports. Their top export markets are not completely dominated by EU nations. Neither are their top importers. They will likely suffer increased inflation in the near term, but exports will increase due to more favorable currency exchange. The primary source of legitimate worry appears to center upon London and finance.