How's that going to work when 90% of we Europeans only speak are own language. And armaments are a mix of many countries unlike the USA and Russia which are all there own makes.
You are getting it wrong. The new EUSSR army will not have those problems. They are going to have Toyota pick ups, rocket launchers, and Kalashnikovs. They are arriving in their millions and are ready to fight ... anybody who doesn't do "the will". Here is a picture of them training to cross the channel with the advance scouting parties.