The movie is full of smart plots.
"using the one thing they wouldn't fear the most, themselves"
Not only that but the fact that they destabilized the Earth first by destroying the Moon. The earthquakes, tsunamis and hunger took care of everything before the invasion.
The constant asking of "are you an effective team?" the clones can't spent too much time on Earth, because eventually they'll regain their original memories. Add to the fact the false promise of returning to Titan, not only this serves as giving them false hopes but let us know that when those 2 last weeks ended the clones would've been eliminated. That's what happened the moment Vika said they weren't and effective team and that she was having doubts, she got killed immediately. It served as a fail safe for the aliens.
Human Instrumentality Project
Sacrificing older life to create a new lifeform blessed with the fruit of life
Last edited by RagnaroK; 05-07-2013 at 12:02 AM.