As a fanboys perspective Star Wars side note...

What Officer would have the balls to order Vader around?! Unless it was GM Tarkin himself, I just can't picture it.

Okay, now back to reality. As you were internet.

For Vader it's less orders and more tentatively provided tactical suggestions.

Piett, "Perhaps if we follow an alternative way of thinking?"

Vader, "What do you mean?"

Piett, "Begging your pardon, sir...but if you were to double up your efforts on those two troopers over there, I'm certain that them falling into equal halves will increase our efficiency to move into the power core."

Vader, "Hmm...this plan had better not fail, Admiral Piett."

Piett, "Y-y-yes sir. I mean no sir...it won't! I'd bet my life on it."

Vader as he walks down the hall igniting his lightsaber, "You already have..."