Yea, I see your point. We start 8 guys and 1 DE. We can keep 18 on our roster and two additional guys if they are on IR. My thought is to get a decent DE somewhere in round 7 or so and then wait until the end of the draft to pick up DE's. You never know who is going to be surprising and they have more potential then say a backup kicker or TE who are always around for me to pick up during the season if mine goes down.
I did some analysis of my draft last year and noticed that a lot of the guys taken late rounds (14-18) were wasted picks. Some of them never even play. I would rather have 3 DE's on my roster. I can always play the one with the best matchup and trade them if I need to.
You are right though, where is the quality of the top RB's over the top DE. I see our point.