I'd much rather just have someone that is great at drafting. Great players make coaches look great. Just look at the Steelers WR drafting over the last few years compared to someone else like the Jaguars who have also drafted lots of WRs. The Steelers drafted S. Holmes, Wallace, and Sanders. All big contributors even though Holmes had off field issues. The Jaguars drafted Matt Jones, Reggie Williams, and RJ Sauer, all WRs in the first round and all huge busts. If the Steelers made those same WR picks, it wouldn't matter who is coaching. It's also one of the reasons the Pats are so good every year, they don't miss on OL picks, don't miss on defensive picks, etc. It's why they can let great players like Samuel and Seymour go, and still be really good. Drafting right is everything.
The Steelers also drafted Limas Sweed in the 1st round not long ago...
And maybe with the right coaching Matt Jones or Reggie Williams could have been stars...you'll never know.
But I agree with you having a great draft is just as important as a good coach...and the Bears drafting has been terrible the last 10 years. Angelo could definitely learn something from the Pats.