It's already difficult to get everyone online at the same moment in Dune because the community isn't as active or crowded as Red Alert 2 or Tiberian Sun, so I think this kind of tournament would be the best option. And I don't think it's such a bad idea to have a ranking from this, because if it would be that bad, then big organizations like the World Cup, Champions League, Europe League etc. (where money plays a big role) wouldn't use this system neither.
The tournament will start on the 1st of July and it's nice that you are able to record/comment on the matches and we would really appreciate it !