I may have missed something but the majority of UK airlines fly into European airspace so learning to fly in the UK is no great advantage. Furthermore, the majority of airline flying is in Class A, B & C airspace; UK trg and hr building is almost exclusively in D-G which is very different.
Finally, I did my trg in about 4 different establishments and am now employed bya flag carrier on the Airbus which kinda blows some of the other theoriesout of the water!