if you're having so much trouble go with a PuG

can't believe I actually recommended this but you seem to have difficulties using H&Hway.
but if you wanna stick to H&H the most important thing is to know how to control your heroes. that means maximizing the usage of the 3 different stances(aggressive, guard, passive) as well as flags(for each hero and for all).
as for your H&H choice, it depends on your own profession. you will want a high damage build to handle all the breakdowns of the titans. AoE will greatly help you along with some distruption, especially for the Sparks.
here is my recommended H&H team for Hell's Precipice:
Heroes:
2 Ele nukers, I find heroes are best at using the Savannah Heat version but use whichever suits you best.
1 Ranger, mainly an interrupter build with Concussion Shot to add daze.
Henchmen:
2 both Warriors
2 Monks
of course you are interchangable with any of the H&H in here, in which case you should make minor adjustments, say you're playing Monk than you drop 1 Monk hench for another ele.
remember to lock your Ranger hero onto a priority caster(monks and eles) to completely shut them down while the rest handle the smaller threats.