Recently we attended a slightly different Warhammer: The Old World tournament. This was an event with teams of 3 players, where each round the team would be matched against another team. A matching system similar to that used by the ETC was them employed to determine which armies would face each other on the tables, and the results were then tallied together at the end. A rather gentle "capping" system was in play, meaning that despite each game being determined by a 20-0 system, the overall team results would never be more than 20 apart. So the team would always get at least 20 points, and could never get more than 40. This essentially means the teams move around on the leaderboard exactly the same as solo players would with the normal 20-0 scoring system. It was a 5 round event over 2 days, and there were 14 teams in attendance (so 42 players).
There were some interesting rules in place for army selection. Every player in the team had to take a different race, and they couldn't duplicate magic items across their lists (so only 1 Ogre Blade between the 3 players). You could also only field a combined total of 8 levels of magic, and characters were capped at 600 points despite the armies being 2000 points. There were also some rules around spamming duplicate choices, but it all added up to mean that army selection was interesting. How would you spread the magic levels across the armies, which ones would work best with only 600 points of characters to work with, and did you need to look at armies like Dwarfs or Daemons, who don't need to fight over the magic items?
We ended taking a combination of Empire, Orcs and Goblins and Warriors of Chaos. Across the event there was a pretty wide range of armies in play, with only Wood Elves, Ogre Kingdoms and maybe Dark Elves not represented at all. Amusingly there was an identical over-equipped Chaos Lord on Dragon that managed to make its way into 4 lists (including ours).
This was my list. Honestly not the most carefully designed thing in the world, but I managed to play a couple of practice games with it, and I didn't do too badly in those games. I also liked actually having some infantry... Unlike my teammates.