The EU pushed through the Euro without the necessary political and technical measures in order for it to succeed - i. e. Fiscal union, a joint budget etc - on the supposition that crises would arrive that would mean these could then be put in place. Good luck with that, see Greece, Italy and the German resistance for that.
The current European army is another example of the EU Commission seeing no crisis as to good to waste - namely Brexit and Trump's omission of support for Article 5 - and attempting to do the same for an integrated military force. As stated the numerous problems of funding, procurement, chain of command - let alone a joint agreed foreign policy - is ignored.
The difference being Euro problems can be kicked down the road - a military emergency such as an invasion of a member nation being slightly more pressing.
IRRC it was Kissinger who asked, when there is an emergency, who in Europe do I call? In this case, if there is an emergency in Europe, who makes the call?