Probably not. There was most likely 3-4 main groups, the main alliance that was killing AV, an outside healing pt for the main alliances tanks, a party/alliance for the pets, and than extra people they would sub into each group as needed for hate reset and deaths.
Most groups that did kill AV were 40~50 members, some went in with even 80 or so when it first came out and CFHed it and tried to zerg it.... Most of these efforts consisted of multiple shells.
As for QCDN's endgame scene... there are shells, NA and JP alike, that have taken down everything except AV at least once, so if you are measuring skill/quality of a linkshell by kills alone, there are quite a few decent options. Activity level, member compatibility, and which area of endgame the group focuses on, I think, are probably very important and personal factors to consider though. Also, the distribution systems vary a lot, and are generally quite different from WOW's (as there are few instances, and people can have multiple jobs) so... researching those would be good to do too.
oh, and a few corrections.
There is one group on this server that did kill AV, they are/were (maybe not together anymore?) a Japanese Dynamis LS. Don't remember the name
And... in response to some of Romps post

Kaizen has not killed AV, it never popped for us before the wall and Wynav tricks were fixed. Also, we are a mixed shell... EU/Asia/NA/SA/Australia... everything.