Just throwing out a few ideas.
I used to play on a private server (years ago), and the GMs from time to time would summon people to Blade's Edge Arena and host a duel tournament. Sure, some classes will have an obvious advantage, but if you aren't confident in your abilities, don't come, simple as that. So my idea:
1v1 dueling tournament. But no single loss elimination crap. You get 3 strikes and you're out. Random matchups, so no QQ about who you're against. After half of the competition has been eliminated, new game. 2s time. You are again randomly paired (so no picking your best friend / most op in bracket as partner). Double or triple elimination this time, with randomly selected opponents. It goes down until there is one team remaining, and they may choose to either split the prize, or to do best 2/3 dueling with winner takes all. Something not simple such as just a wsg, and lets everyone have a fair chance to win, not just whoever had the best team.
Also, random matches can be done with /roll, have everyone /roll 1-1000, whoever you roll closest to is your partner/opponent.
I can improve on this idea if anyone likes it.