I see a lot of questions here and I am going to put my two cents forward-
First and foremost, England have to accept that they have been lopsided with their preparations for the past ten years. It is unacceptable that you either start becoming a red ball specialist team (until 2015) or a white ball specialist team (now) and strike no sort of balance.
Secondly, having two coaches for different formats or a different support staff is not a solution. This obsession surrounding big ticket names in cricket team balconies seems big in England and Pakistan of late but it's the cricketers who change fortunes, not coaches. You need one balanced coach who works like a friend with cricketers who knows when to give gun cricketers a break and try fresh people.
Thirdly, this logic of playing people who have played 12544363 test matches in dead rubbers needs to stop. The selection for the last test is a fine example. When are you going to try an Ollie Pope, a number 3 or a Sam Curran? Broad's cricket doesn't need the third test to prove he's a quality test match bowler in these conditions. It's a fact. Also, Sam Curran was the man of the series last summer against the number 1 test team and he hasn't played a game this summer. Isn't that kind of stupid? Woakes was dropped after one bad test for Overton which is rubbish selection after Woakes bowled his shoes off in the first two tests! Jason Roy and red ball cricket don't go hand in hand. Period.
You cannot mix white ball and red ball cricket. To amplify- Bairstow who is a far better batsman than Wade is hiding behind his keeping gloves so that he can make his 30's and 40's down the order and keep his place while Australia have the confidence to play a Wade as a pure batter. THAT in itself says a lot. They dropped Khawaja who has been their best test bat while the three banned test cricketers couldn't play. Bairstow and Buttler both cannot play together if they both think they can make it with 30's and 40's. One of them has to put their hand up and be a proper number 3/4/6 depending on where Root prefers to bat and make tons.
Speaking of tons, Root needs to go back and take a look at what Smith has done not just in this, but Ashes overall and see what he has done. Again, he has the same ability but he needs to convert and be more ruthless and hungry almost. I think he's a good lad and a fine cricket brain. Let him keep the job for now. Give him time. But, the clock is now ticking for sure because of this shambles.
This English team is blessed with insane ability and depth and I think they have not fulfilled their potential. It says a lot when they were the first English side to become world champions!