That is my criticism of them moving on from O'Shea.
You implement a system you know is complex and takes awhile to get to work. The offense struggles at the beginning of the season but outplays the #1 defense in the league at the end of the season.
The decision to replace O'Shea was obviously made before the Patriots game, but the Patriots game proved that it worked in the long term.
What we don't know is all the stuff behind the scenes. How did O'Shea and Flores get along? What direction did O'Shea want to pull the team in? How was his work going with the players, particularly the young players?
One forward-looking criticism of this team is that very few young guys stepped up. When you get rid of as many vets as the Dolphins did, you hope your young guys step up and make their presence felt. With a few exceptions, that just didn't happen. The remaining vets really stepped it up -- Parker being the prime example (as well as Fitz), but even guys like Gesicki and Eric Rowe.
None of the young receivers, running backs, or linemen showed much potential. Ford had a couple of good plays on offense, but considering the dearth of receiving targets and the willingness of Fitz to throw the ball, it was still disappointing IMHO. That young first round quarterback we picked up didn't exactly light the world on fire, either.
Things looked a bit better on the defensive side of the ball, with Needham looking like he could possibly develop into a decent starter, Steven Parker looked solid to quite good at linebacker, Wilkins (our first round DT) looked reasonable, and so on.
Anyway, point being that there's a lot we don't know and what we do know about the development of our young offensive talent has looked pretty bad.