It's too bad R=U is fake though, it makes the story a million times better and a lot deeper. But staying on topic, dreams are always about memories of a sort. These memories don't have to exist to be there. The fayth and Yu Yevon all remember team zanarkand facing other teams, the memory of those teams are still there. That being said, the other teams, I imagine, don't have very good drafts seeing as there's no one else in their memories (probably)