i run with a powertech merc and a healing sorc
Are the PT and merc your DPS classes, or is the PT the tank? It's a pretty well knon fact right now that PT tanks put out more DPS than Juggernauts, which may also be a problem.
All I know is, the first time I ran HM BT, we had a Sniper and Assassin and all the bosses were loot vendors. Ran with a Vengeance Jugg and fresh 50 Merc (dunno the spec) and got eaten the next time.