BLU/THF was better against PW due to not suffering from double weakness.

Also, I know at least one group was able to hold AV indefinitely at level 75. It required pretty much perfectly geared Aegis PLDs idling in mdt/mdb/int gear, but it could be done. The problem was that no amount of heavy DDs were able to damage it fast enough while surviving Meteor. Even combining two of the best geared LSs in the game at the time they didn't have enough relics to throw at it.

Alexander was released shortly before the level 80 cap raise, if I remember correctly. The idea was there to use heavily buffed WARs in combination with PD to kill AV within the 90 second time limit, but the server merges had happened by this time. Neither LS had the active membership to pull off the fight (3 alliances plus rotating buffers) by this time since one LS had moved to a different server in order to be more active in HNMs. Shortly after the 80 cap increase a member of the first LS who had been leading the push to defeat AV moved servers and joined what had been Volume, recently merged with another LS in order to have more active members. Shortly after that they recorded their first 'legit' AV WAR kill, using the super-secret tech of DNCs and SMNs that is now well known.

Maybe other groups were doing similar things around that time, but to my knowledge Failure's group was the first to pull it off.