Although not perfect surely they have intensive interviews in English and simply have tests they make all employees take which test numeracy and literacy along with logic?
At the company I work for there are plenty who are from EU and all when they join the UK division or another countries have to take the tests..

One of the major reasons sited is Health and safety. As you say if you cant communicate

Thats how most UK companies i know get round making sure those who like you say they cant test on English. But of course it costs money

Far to many excuses where people hide behind the blame it on the Eu although the EU does it best to make a nusiance of itself