I accepted the first friend request I ever received, a guy from Turkey I played against in the Cup, and who may no longer be active. That was season 1.
Also in season 1 I friended 3 players, Brazil, Belgium, and Spain. I'm now in a league with those 3 but it appears only the Spanish guy and I will be promoting.
I took a friend request from a German in season 3 who is 2 levels below me, and I have a real life friend who is just starting at level 1 right now.
This will give me a little variety in levels. Hoping to find a couple more Americans on my server though.