Does this work on Silver? I've tried to do this in Gold pugs and I constantly die, clearly I'm not quite up to par yet. Also, is a Predator or Phalanx an okay substitute for the Carnifex? My Carnifex is only at rank II and doesn't seem to do enough damage, not to mention the lack of ammo has me running to an ammo box after every wave.
I've heard it's a good idea to put the decoy in the archway, that is the archway to the right in the image with the grab symbol. Apparently the Geth coming down the stairs outside see the decoy first and attack it, while the ones coming down the stairs inside mostly focus on the decoy as well. Is that legitimate advice, or is someone trying to pull the wool over my eyes?
This is why I liked co-op games so much, the community offers great advice as seen in this guide, instead of going on about 360noscopes and K/D ratios.