In the past, the Bills have simply been too lazt to work out the complications of a trade-down.
This year, I agree that it makes a lot of sense to trade down. I mean, there are about five first round OTs available and the best guard in the draft, Iupati, looks like he can also play tackle. But this is the Bills we are talking about. If there is a trade-down, it would give me a lot of confidence in Nix and Co.
On other hand, no-one is going to want one of this year's QB as high as 9. However, if McClain was still there when we pick, Denver or Miami might want him.