Two man left tournament took about year and a half (or even longer) to complete, gladly 2v2 Smash-up was much faster treat. As a lesson learned, I believe that best format for invitation 2v2 tournament would be round robin with odd number of participants. Playing simultaneously against everyone with equal number of games as team one and two. To limit number of matches - teams face each other only once.
With 5 teams that is only 4 simultaneous matches, with 9 teams it would require 8 simultaneous matches that might be too much for many of us. All matches were played on single map - and team would be awarded map specific championship.