vanquising old ascolon

evening

I am trying to vanquis old ascalon with 3 hero's.
But i run into a problem.
At some point there is a large group of crawls with 4 crawl shamans in them.
They heal like crazy, and i have no idea what i can do to kill them.

I my self am a elementalist/asassin.
16 Air Magic
12 Deadly Arts
4 Energy Storage
“You Move Like A Dwarf!” | “Finish Him!” | Chain Lightning | Lightning Orb | Glyph of Lesser Energy | Air Attunement | Assassin’s Promise | Ebon Vanguard Assassin Support

the hero builds are:
[build prof=N/Rt sou=10+1 cur=12+1+1 res=8][Spiteful Spirit][Insidious Parasite][Enfeeble][Barbs][Rip Enchantment][Weapon of Warding][Signet of Lost Souls][Death Pact Signet][/build]
[build prof=N/Rt sou=12+1+1 res=12][Reaper's Mark][Weapon of Warding][Mend Body and Soul][Spirit Light][Blind was Mingson][Life][Signet of Lost Souls][Death Pact Signet][/build]
[build prof=N/Mo death=12+1+3 sou=9+1 hea=9][Jagged Bones][Animate Shambling Horror][Animate Bone Fiend][Death Nova][Patient Spirit][Dwayna's Sorrow][Cure Hex][Signet of Lost Souls][/build]

Can anybody help me out on what i need to change or what i need to do to get that group down?? Its the only group i have problems with, all other mobs just die extremely fast.

thnx to any one who replies

You can swap in a ranger hero and Daze them and cornernuke, or simply cornernuke with a snare as you're ele.

Cornernuking - see to that you gain aggro, which is dependant on armor first (buffs included, doesn't stack unlimited anymore if i recall right) and hp (healthpoints) second (there are other factors but those are the main two), you want to be the lowest on armor if you are the one managing aggro (usually the tank, who if s/he knows what to do does that with SY, Save Yourselves, etc). Then place a hero at a wall where there is a corner gain aggro - follow the wall and move backwards until they're all balled on the hero - as they use ranged weapons it might be a lil tricky as you have to account for that.
The "trick" is just that to get them together, a ranger with broad head arrow and epidemic (mesmer) or several different types of interrupt mesmer can do quick work of them then. A nuke with them snared should do the same (snare is any skill that slows down movement speed).

Aggro management +daze or massive aoe dps (area of effect, damage per second - nuke) should do the trick. ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° [Edit] Spelling etc. ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° °