Help with Frost Gate Hard Mode Bonus

ive tried this 10 or so times and im getting nowhere. ive been using heros/henchmen to do it and it doesnt seem to be working. ive tried pulling the groups one at a time and ive tried fighting them all head on and neither seems to work. my current setup is

Me - Echo SS necro
Heros - varied between a MM, 2 savanah heat nukers, and a monk(tried a few different builds)
Hench - usually the healer and either the mage, tank, or mesmer.

does anyone have a decent hero hench strategy to use for this one? as well as what to do with them once i get to the groups?

Hi, for me, I ran almost always the same heroes for all HM Tyria missions.

1) SS Necro (that can be you)~make sure you pack one enchant removal
2) MM Necro
3) An interrupt Mesmer~I really like the Power block, empathy diversion mesmer also with an enchant removal

So, since I was monk I would suggest your last hero be an LOD monk with dismiss and spirit bond or prot spirit. Then, I would round out the group with a fighter hench and the healer hench. The key to this bonus is to effectively and quickly take down their awesome healing provided by the doly riders...this is where the chant removal and interrupts come in. The SS, MM and empathy is more than enough damage to quickly wipe them out. Good luck although i think you will find it quite easy now

Oh and always try to pull the groups since 3 of their Dolys can heal very, very well.