But nobody knows how the OPC teams measure compared to EU/NA/KR. It's impossible to rank them, they never played in the other scenes. Rogue (and nV to some extent) is the only team that plays on all major scenes and it's kinda used as a benchmark to gauge how teams measure cross scenes. That's the weakness of those rankings, there's too few cross region matches. Hopefully most NA/EU will play at the OWL then those rankings will have more meaning. You probably still won't see teams from other minor scenes, unless they participate in tournaments that teams from other regions attend.
Some spots in those rankings are arguable, but overall it's a good list IMO.