I heard this from a few others I ran with for ECHM, that a "double" double distruction is a sign of a problem.
One of our few problems on the Fire and Storm is the 2nd double D falls too close to defensive systems and auto quick drops the first lightning bubble on the tank hitting the dps with no defensive systems cast bar.
Can u take down storm and fire while getting two double D's per phase?
Are there other successful methods other than the 4 and 4 split?
What has worked for others doing HM storm and fire?
P.S "getting another guild" is not a solution
Honestly, it sounds like your dps is lacking. You don't need to get another guild, but you should have someone who's skilled at their class mentor your dps (have them fight the training dummy and they can help tighten their rotations). Surely your Sith Warriors/Inquisitors can find a Master, and your Operatives a trainer and your BHs... well they can pay someone for lessons.