Good points, but the difficulty I am having is that both with Davis (OL) and with Cosgrove/Lee, he was quick if not downright immediate in the replacements. The case with Roof seems to suggest Brew was not quite that prepared for his departure, but like Hate Monikers mentioned, he had a recent search list ready to go.
For all practical purposes, lets just say Dunbar was forced out, yet Brew does not have the OC yet to replace him.
My suspicion is that Brew was targetting Heupel, and did not have plan B quite ready yet.
Really not trying to slam Brew, since I believe he does need to do his homework and get the right guy. I just think, given his nature with recruiting, he is approaching getting an OC the same way!