On just offense, DPE will be an important piece but not the most indispensable - that still goes to TA who controls the offense/calls the signals, has to make plays both throwing and running the ball (DPE too against NW), make zone read decisions + his progressions, be the motivational leader of the offense, etc. If you include special teams too, though, I'd say you could make a strong case that DPE is right up there as the most indispensable player on the team with all he does on offense and returning.
Totally agree with what you said about Gerry.