Two points from me---
Firstly, I don't think need to be same server to be in Friendly Competition. With the join code, anyone can join if I'm not wrong.
Secondly, Facebook is not the correct (good) way to join. Google Play is. I lost a very powerful club completely as my facebook account can't get in as they insist I verify with phone and photo, which I refuse on principle. So I lost a big club built for two years (real human years) , overnight, just like that.