"There are far, far fewer British pilots working in Europe than European pilots working in UK."
Are you sure about that? Where do you get your figures or is it just a feeling?
I think that it's a reasonable assumption to make.
Which do you think is more likely to be higher, the number of pilots from one country (the UK) who are working in the rest of the EU or the number of pilots from the rest of the EU (27 countries) working in the UK?
I personally know at least 12 pilots (and that's just those that I can remember off the top of my head) from an EU country other than the UK who are currently employed here on permanent contracts but I can only think of 4 who have left the UK and are working in mainland Europe.