In the "Scrimmages" box in the bottom right of the "Manage My Team" page, there are four teams listed to challenge to a scrimmage. The first one is from the user's country, the second one is from a country where the user already has a flag, and the fourth is from a scrimmage ad. The third is supposed to be from a country where the user doesn't have a flag; however, right now all of the teams showing up are from countries where I already have that flag.
I hope that makes sense.