Acting as a union Germany, France, and UK would get everything, some hand outs for Spain and Italy, any profits skillfully funeled through Luxembourg, Lichtenstein, and Netherlands. The general population getting low quality tat "Made in China".
Somewhat aside: it's a bit of a shame the netherlands gets the blame in these tax-dodging stories, because the issue is actually that laws differ between countries (i.e. countries with laws identical to the netherlands aren't vulnerable to the tax dodge), and as it so happens, the netherlands' tax system is... not quite as crappy as that of most other countries. Still crappy, mind you. Just not as bad.
I.e. the appropriate solution would be for (e.g., to pick on a particularly bad tax code) the US and germany to simply dump their tax codes wholesale and copy the Netherlands, rather than the converse. Because seriously, some tax codes are just asking to be abused. Plug this hole, wait for the next one...
The cynical side of me doesn't think it's coincidental that the loopholes are so gaping. Oh well.
Right now, industries in Eastern Europe are "not allowed" to trade directly with China, India or Russia. Anything they produce and is sold outside EU must go through German or other western company. Guess where the profits stay.
See also sanctions against Russia: the trade of everyone _except Germany_ went down; overall the trade is the same. Cui bono?
Yeah, sure. And the fact that Bulgaria with Hungary cannot have their gas pipeline (South Stream), but Germany can (Nord Stream 2), is just another piece of fake news. Right?
It is certainly not about who will control the trade, everything is just coincidence. Sure thing.