This is my position as well. With Josh Allen, it is very very difficult to lose more than 7-8 games a season. So if the replacement is a total bum, we will still be on the fringe of a playoff spot.
Having said that , I am not sure the replacement of the coaches alone is sufficient. If McD is higher on the decision making chain than Beane, he cannot be fired by Beane. If Beane is higher, he stays and McD is gone, will things really change with the drafting process and allocation to resources between O and D?