I got a hard Brexit with Lincoln when I was still at a lower level. The knock-on at that level is that it limited my transfer dealings. The top leagues aren't much easier, as you have to go for more established players to guarantee permits. Essentially I decided the best way for me to go was to work on getting GB/Ire players only. It's tough trying to challenge the top top teams, but it won me a Europa League, so it's not the worst policy in the world.