There should be KPIs with which the board can hold the DoF to account.
I still think any coach worth their salt should be able to get the best out of players at their disposal. If coaches need a perfect mix of players to get the basics done, they should not be here.
It's up to the board and the DoF to work out the recruitment strategy. We can only judge decisions made, which is easy with hindsight.
We must remember, though, that a 'DoF' does different things at different clubs, and they are responsible for a lot more than just recruitment.