Нет, все превознесения должны быть получены одним персонажем. По-крайней мере так пишут в англ. комментариях на вовхеде.
Сводка
As of 8.1, you still need to complete this entire achievement on a single character. I had bloodsail on one character, and all the rest on another and did not get the achievement. Confirmed with a gm that this is intended.
“I did some digging to see what I could find for you. Insane in the Membrane is intended to be one of the hardest achievements in the game, which is why it’s so prestigious and very few people have that title! It is intended to be completed on ONE character.
For other achievements, you are correct - things like Pathfinder should count your progress across characters. For this special one, though, we do still need to complete it only on one character.”
https://ru.wowhead.com/achievement=2336/%D1%87%D0%BE%D0%BA%D0%BD%D1%83%D1%82%D1%8B%D0%B9#english-comments