The DoF should be putting in place a strong scouting and recruitment team, and then backing them at least as much, if not more, than the manager when it comes to which players to sign. Obviously the manager should have some say, but if he wants to spend a huge amount on a transfer while the scouting team are saying that that player has significant weaknesses and provides a list of players who they believe are more likely to succeed and are available for a much smaller fee, then I know which one the DoF should be listening to.
The one defence that I do have for Murtough is that it takes time to build that scouting network and player analysis database, so I can somewhat understand him relying too heavily on ETH in the short-term. But that reliance should have been decreasing every season, and we haven't really seen any evidence for that happening yet