I like the suggestion of NZR select the head coach and then set about appointing the assistants with input from the head coach, rather than complete free choice.
We need to spend some time and money defining exactly what the structure and requirements are of the assistant coaching setup with properly written job descriptions and metrics for measuring performance.
This seems to be what Rassie Erasmus has done with SA. Their coaching setup is way more complex than ours but they have a well defined structure and everybody seems to know their role.
We would have to review it every 5 years to make sure it is ahead of the game or at worst keeping up. I think this is a big part of our problems. We caught a break on the rest of the world when we appointed GH, Hansen and Smith and our coaching setup was better than the rest of the rugby world. Unfortunately this lead to complacency and the rest of the rugby world looked at what we did refined it and now have better coaching structures than us and we are trying to do the same thing we came up with at the turn of the century.