I don't think there is a one size fit all for good and bad managers.
I think Sean Dyche is a good fit for a certain type of club. A smaller club where staying in the division each year is their equivalent of winning the league each year.
A club that has bigger ambitions than that seems not to be the right fit for him. He doesn't appear to be flexible enough to change his system to allow better players(when he gets them) to express themselves in the best manner. They have to adapt to what he wants.
I think he was the manager we needed for a while, he dragged us clear of the relegation which was certain if we stayed with Frank Lampard.
Last season he did well and helped keep us up in spite of everything that was thrown at the club.
However, in the summer we did keep our best players and did add some talent to them but you cannot see any improvement or change in style.. or results unfortunately.
I felt at the start of the season that this season was an audition for him to get an extension to his contract.
I don't believe the audition has been successful.