Since long time you (blizzard) made those server join against eu servers.
The problem is just one,they join almost as a premade that makes almost impossible to win them as a pug.
I bet that everyone lose 95% of bgs vs german or french ppl.
Now,to be fair or let them join with us and mix the players otherwise let them que only vs them like germans vs germans,french vs germans etc etc. Otherwise you are just ruining everything more than you did already.
They are horrible players,about 90 % of them,but playing with ppl that talk your languange make them so strong. As I said,it's almost like fightining a premade since they even have less servers.