We only got to do 3 tries before people had to sleep, and didn't get a win, but we did go from flailing around with 7 people in our first fight to getting it down to 30% health in the 3rd fight, and I believe we could have won if the AOE hadn't for some reason faltered towards the end. But anyway, here's what we ended up doing for a strategy:

Take in two people to kite/kill the little generators. First kiter goes in, pulls Vanguard, starts running. Second kiter at the same time takes down a generator. Everyone else piles on top of the central generator and goes nuts on it. Anyone who can AOE (especially warriors and archers/bards) AOEs the adds in the middle as they spawn. Since the Vanguard will pick up hate on whoever kills the small generator, people who are AOEing may accidentally get the kill and need to be ready to take up kiting for a bit as well. While everyone else is killing in the middle, the two kiters take turns taking out a generator and kiting the Vanguard.

This was going SO smoothly until about 30% health left on the central generator, then like I said our AOEs started faltering and the central group got overwhelmed by debuffs and adds. But it was working so smoothly up until that point that I feel pretty confident we'll get some wins tomorrow afternoon when we all log back in. Really fun fight!