It's funny to see some of the usual suspects dismiss the Oliver pick as a "no brainer" that "fell into Beane's lap." Good luck is typically the result of good preparation.
Yes, once Oliver was on the board at #9 it was an easy decision, but the reason the Bills were prepared is because of their work leading up to the draft and the various mock draft scenarios they played out internally. They were prepared for whatever happened and did not panic or trade out of the spot, and wound up getting a top 3 overall talent at #9 who happens to be a freaking perfect fit for this team.
If you want to say the Bills got lucky go ahead, but they created their own luck.