I got a hard brexit and it has made the game soooo much more interesting. In previous FM's I could dominate for years simply by poaching the best regens but that is no longer possible. I still buy regens but I now have to loan them out and wait until they get international caps before they have a chance of getting a work permit.
It is a shame sometimes when you find a world class 18 year old regen who you scouted but can't play him for years but its a really interesting challenge.
I mainly rely on my own academy now with the occasional "big" signing or two if the team starts to struggle. I think you can still sign foreign players if they play a lot for their country? Or maybe I didn't get the hardest brexit but I can still sign the very best players abroad, so long as they have got so many I. Caps.