Personally, my linkshell and I made something of a routine out of that assault back before the level cap bumps. We have a paladin hold hate and stand against the door, and everybody else brings whatever weapon they've been wanting to skill-up.
I can tell you from after a few days ago that it's not really beatable with 4 90's either, at least not without squicky tactics like pulling all the crawlers someplace out of the way and logging out. After prior frustrations, we took the time to kill three of four erucas that were in our way, and we only ended up with about half the troopers fed. I'm going to wait until I see a full six available in my linkshell before suggesting it again.
They'll let you trio Salvage now, but some of these Assaults require a full party no matter what level you are.