Well if there wasn't a balance in official there would only be 3 classes each of them with the same stats.
Balance in official means knowing everything about your class, if there's 2 partys pvping for over 20 minutes that's called balance, they knew their class since in official every class as a role in the party and they could keep being alive.
Now if there's a party killing other partys, well you can't call that unbalance but knowing how to play.
The balance always came to the players and how they choose to play. True, there's classes that just can't kill every other class, that's part of the balance because Lineage II was never meant to be played 1 vs 1, we do it and if we die by a class which wasn't supposed to kill us doesn't mean that there wasn't a balance in the fight because it all comes to which one is playing their class better.