Considering how much OPtimus had to handle in TF3, as far as killing off cons, honestly Shockwave could have killed OPtimus if he could. I'm almost positive shockwave was way heavier or stronger than Megs or Sentinel, but the helpf of soilders and the like, Optimus got a free entrance to take him out. Surely if it had been different, the Wreckers would probably not make it out alive against Shockwave, and Optimus would probably not have been able to take him out alone. The remaining autobots and military would've had to kill Shockwave, leaving Optimus nearly dead from a brutal attempt to take him out. We all have different opinions, but this is mine.