I thought I was undergeared in a run last nite till I read this. This is exactly what our group was doing and we ended up wiping as I couldn't keep up with healing demand. Might have been a bit of both as the tank was going down really quickly. Funnily enough, did the same HM FP a few days earlier and that group knew the strategy of bringing the boss up top and using ints on the headshot - that was a walk in the park and used the same toon/gear as last nite.
Should've tried this back in early January when the fight REQUIRED two interrupters for the headshot or it almost couldn't be done. All you need to do is put down your pisspool and light heal the group and you're good through the volley.
Another trick for those new to the fight is to have everyone run around the boss up to the bridge (where you saw the ship captain die in the beginning) and have the tank run to the big blocking console behind the boss' starting point, aggro the boss, hide behind the console, let the boss come to you and then begin dps. The adds (which were a bi-tch way back when) will sit there doing nothing until Ironfist is dead and then you may kill them at your leisure.