I think it is a little like the 'chicken or egg' situation with coaches and players! Do you first get the coach and build for him, or do you get the players and then try and fit a coach in with them. A decision needs to be made which situation is best.
We have a similar issue now at Dortmund. Before, with Klopp, there as a definite policy and methology to the squad building, done very much for the style, and it worked really well, and it was possible to do without spending like crazy. But that was allowed to happen cos it was a long term process, and not often do teams have that loyalty with coaches (both from the team and the coach) so it's hard. But now we see the opposite situation, where we have quick turnaround of coaches, all with different styles of play, and the team is a bit all over the place because of it.
It is impossible to change the whole team, Everton have plenty of good players a good coach can work with. Coach and sporting director need to be totally on the same page though. Until that happens, there will always be trouble, I saw how much trouble that causes at my club in the last couple years, very quickly things can go wrong. But in the same sense, things can be improved and fixed quicker than imagined too.