It might be overstating it to say that the DoF comprises people with no economic background. There are people there with qualifications in economics, although I don't know how many. In addition, many of the generalists are quite bright people who might not have formal credentials in economics, but have the intellectual capacity and the motivation to become well-versed in economics.
I would agree with that. A lot of 'economics' is really just a practical grasp of what's going on domestically and globally, allied with the intelligence to analyse it and come up with good advice.
I heard, from the horses mouth, a couple of years ago that officials in the Dept had been warning Govt for ages of the dangers of their economic policies and were being brushed aside. I am very glad those civil servants have been vindicated. They had effectively been slandered by short sighted, greedy, power hungry FFers.