It's a design feature that's really only applicable to HSTR. The point, to test a guilds breadth of toons so they don't succeed with just having 4 or 5 really strong teams.
It doesn't translate well to the lower tiers and is one of the ways I think CG can tweak the raid below Heroic. It's a little annoying, but once you carry into the next day you should be able to wipe it out pretty quickly. If you want a great score, get KRU. Zeta if possible, but if you're doing T3 just getting KRU is enough. Hopefully he has unbreakable will so you can fire that off and do some decent damage with the rest of your toons.