I'm going to echo the likelihood that the cause is having two blm. But it's not necessarily the fact that you have two blm, but that either or both blm are...not that skilled. Note: I am assuming the entire group is similarly geared, 125-130 with zodiac or zeta (however, 125-129 should be where everyone is at this point), so gear isn't the issue.

You should parse or get a video of the fight and try to find the weak link, and figure out how to strengthen it (dummy fighting, more practicing while moving....worst comes to worst, replace)