Just for the conversation sake.
we are running,
Honestly, with this setup I'm surprise you're still at around 20% when the 4th male spawns as Jugg and Marauder do some absolutely insane DPS.
I don't think that it's a strat issue as you manage to go through all the phases., its just not enough DPS. Curious though, at the beginning of th encounter does your Jugg or Marauder ever pulled aggro from the tank...as although shouldn't., if they both are going all out then its very hard for the tank to keep aggro at the beginning without taunt back or threat dump from them.