Having two people in Vanguard, 1 who can switch between officer and Engineer, and 4 pure engineer is a great way to keep everything under control...
The two in Vanguard should high dps classes to get the kill streaks in
1. Vanguard will use Bellowing Stun As soon as the boss gets up (Knocks off between 140-180k right off the top)
1. Vanguard will use Rending Bark (32% I have been able to trait for) and will use every 15 seconds
1. Officer/Engineer will switch commanders and heal either citizens or soldiers and place trip wires
Remaining 3 Engineers can decon barricades / upgrade and use trip wires.
Telling Mark, Blade Brother, Oath Breakers, and Damage Banner (Capt) + Rending Bark + Revealing Weakness (Burg) + Bear Traps == All make the really high dps classes doing even more...
For example: I got a 46k Upshot on the 1st boss when everything above was active, which is great with the mits on these bad boys...