update:

So we went in to turn 4 today.. same setup.. decided to go at a strat i came up with myself first which went quite well:

BRD and DRG on knights
BRD and SMN on Soldiers.. SMN switches to next Soldier when first ones shield breaks.. it just occured to me that if we usually only have 2 phys DPS on the knights then they will not miss the second BRD who will be helping the SMN..

I think a strat where the BRD switches to the Soldier once it opens is probably a better idea though as we had trouble getting the DN down in time for the next phase cos the last soldier was half life when the DN popped

thanks for all the suggestions we will try some of these tomorrow