The part of Terradome where you have to protect the engineers is super hard and almost impossible to beat for regular players who just want to group and run a challenging instance without having to have god like inventory items (all purples, etc.) Even with several groups of Vice Admirals, at different times, on the normal difficulty, we could not beat Terradome Rear Admiral or Terradome VA. It's extremely frustrating and annoying. PLEASE for the love of god, reduce the difficulty at least on normal and do it soon.
Stock up on large hypos,
2 tacs running squad leader kits to fire off rally cry,
sci to use his ground ability when needed,
some aoe, amd if you do the first part right each engie has 2 npc guards to help. just spread out.