You have to see what they can do under different coaching where the changes need to be made. Those probably won't be big changes because they will be insiders from the mired in mediocrity organization.
All coaches should be replaced. You can't have Boston and McEwing out there dealing with stupid base runners. I think Katz can be easily replaced. Tony and the batting coach are no brainers.
You can't get rid of players just to rid them without equal or better replacements. Amazed that even bad pitching is expensive so you keep Gio. They also need to stay away from NL players.