Anyone have any tips on how to defeat these guys? The agent info says that I need to break line of slight with the host but I'm having a bit a touble with these guys.

Just go to the right side where there are a bunch of platforms for cover (there are also two gun racks nearby) and then get each of the twin's health down pretty low (so you can down each of them quickly) and then shoot the agent in the middle. The platform he is on will fall down temporarily. After that down each twin as quickly as possible and then go up to them and execute them before the guy in the middle gets back up.

Yeah, shooting down the guy in the middle (just a few shots will knock down his platform) will keep him from bringing them back instantly - but he returns pretty quickly.

Hiding behind the server racks to the right (facing the guy on the platform) I found to be the best place as well - just make sure to stay on your toes if they lower the server racks.

I had some luck hiding behind the round thing you start behind (and using a gauss rifle to shoot around), but the twins tend to come at you from both directions and that's rather problematic.

Ah. Ty guys :).

further to what the other duders have said

grab the shotgun on wall in the cabinet , wait for one of the agents to get close jump into dart and unload

Yeah, certainly se DART-mode for bursting (and damage resistance) them down.