But I'm not sure it's a fair to say that the Cardinals have compromised on BPA since Brown.
They reached for Brown, and it didn't work out. They learned from that, and haven't reached since.
Yes, Dan Williams was a need. He wasn't, in hindsight, the best player available, but he wasn't a reach. Williams was projected as a mid to late first rounder and that's where he went, It's fair to think that Williams was at, or near, the top of the Cards board when the called his name
Just because the best player available happens to fill a need to is not an indication that they abandoned their plan.