This is the biggest concern. Buying specialist players for a manager that uses an uncommon setup is putting all your eggs in one basket. We have done this for years of course but thats exactly what we are trying to change. The idea that your manager can completely change your style of play needs to stop. It doesn't happen at any other top sides and for good reason. Players are expensive, managers are cheap. Having a squad of players who don't suit each other which has been assembled at vast expense is a mess. The players look crap, its hard to offload them because they look crap and you don't have any chance as a manager.
Every manager comes in, looks at the mess, tries to buy the players they need, slowly replaces a bunch while the morale and buy in declines and eventually it falls apart with half a new squad ready to be replaced again by the next manager.
The only way it can remotely work is if you don't spend huge amounts on the players and if the ones you bring in are technically excellent.