"It was I who allowed the Alliance to know the location of the Shield Generator. It is quite safe from your pitiful little band. An entire legion of my best troops await them. Oh, I’m afraid the deflector shields will be quite operational when your friends arrive."

I’m with Frink on this. The Emperor is making it out as if his best legion of troops await them at said location, so his VERY best troops should be there on standby. Also, this means the Emperor should had already informed his troops ahead of time that a Rebel strike team was heading to the Shield Generator. Trap, right?

Also, this is the damn shield generator control point that’s protecting the monolith DEATH STAR! It’s not some throwaway job to be left to so-so trained troops.

Unless, I’m getting something wrong here. Maybe the Emperor had the actual Shield Dish being heavily guarded and not the control room for it where apparently blowing that part up also blows up the dish…?